AI Hallucination Cases

This database tracks legal decisions1 I.e., all documents where the use of AI, whether established or merely alleged, is addressed in more than a passing reference by the court or tribunal.

Notably, this does not cover mere allegations of hallucinations, but only cases where the court or tribunal has explicitly found (or implied) that a party relied on hallucinated content or material.

As an exception, the database also covers some judicial decisions where AI use was alleged but not confirmed. This is a judgment call on my part.
in cases where generative AI produced hallucinated content – typically fake citations, but also other types of AI-generated arguments. It does not track the (necessarily wider) universe of all fake citations or use of AI in court filings.

While seeking to be exhaustive (914 cases identified so far), it is a work in progress and will expand as new examples emerge. This database has been featured in news media, and indeed in several decisions dealing with hallucinated material.2 Examples of media coverage include:
- M. Hiltzik, AI 'hallucinations' are a growing problem for the legal profession (LA Times, 22 May 2025)
- E. Volokh, "AI Hallucination Cases," from Courts All Over the World (Volokh Conspiracy, 18 May 2025)
- J-.M. Manach, "Il génère des plaidoiries par IA, et en recense 160 ayant « halluciné » depuis 2023" (Next, 1 July 2025) - J. Koebler & J. Roscoe, "18 Lawyers Caught Using AI Explain Why They Did It (404 Media, 30 September 2025)

If you know of a case that should be included, feel free to contact me.3 (Readers may also be interested in this project regarding AI use in academic papers.)

Based on this database, I have developped an automated reference checker that also detects hallucinations: PelAIkan. Check the Reports Report icon in the database for examples, and reach out to me for a demo !

For weekly takes on cases like these, and what they mean for legal practice, subscribe to Artificial Authority.

State
Party
Nature – Category
Nature – Subcategory

Case Court / Jurisdiction Date ▼ Party Using AI AI Tool Nature of Hallucination Outcome / Sanction Monetary Penalty Details Report(s)
USA v. Burke M.D. Florida (USA) 15 May 2025 Lawyer Westlaw's AI tools, GPT4.5 Deep Research (Pro)
False Quotes Case Law (13), Doctrinal Work (3)
Misrepresented Case Law (4), Doctrinal Work (1)
Motion dismissed, and plaintiff ordered to refile it without fake citations.

Counsel later explained how the motion came to be: see here.

Fox v. Assum Israel (Israel) 14 May 2025 Lawyer Unidentified
Fabricated Case Law (1)
No formal sanction; request by court for explanation; partial costs awarded against the defendant 1200 ILS

AI Use

In a filing related to a third-party notice, the defendant cited a judgment that did not exist. The judge clarified that this was not simply a mistaken citation or party confusion, but rather a reference to an entirely fictional judgment. The court explicitly stated: “It is not clear how such an error occurs, except through the use of artificial intelligence.”

Ruling/Sanction

The court permitted the defendant to proceed with the third-party notice but ordered partial costs (₪1,200) to be paid to the plaintiff due to procedural irregularities. The judge demanded a formal explanation of how the fictitious citation was introduced, in order to prevent recurrence

Key Judicial Reasoning

While the procedural error did not warrant barring the defendant’s claim against a third party, the court emphasized that referencing a fictional legal source is a serious issue requiring scrutiny. The opinion signals a growing judicial intolerance for unverified AI-assisted legal drafting in Israeli courts.

Ramirez v. Humala E.D.N.Y. (USA) 13 May 2025 Paralegal Unidentified Four fabricated federal and state case citations Monetary sanction jointly imposed on counsel and firm; order to inform client 1000 USD

AI Use

A paralegal used public search tools and unspecified “AI-based research assistants” to generate legal citations. The resulting hallucinated cases were passed to Counsel, who filed them without verification. Four out of eight cited cases were found to be fictitious:

  • London v. Polish Slavic Fed. Credit Union, No. 19-CV-6645
  • Rosario v. 2022 E. Tremont Hous. Dev. Fund Corp., No. 21-CV-9010
  • Paniagua v. El Gallo No. 3 Corp., No. 22-CV-7073
  • Luna v. Gon Way Constr., Inc., No. 20-CV-893

Ruling/Sanction

The court imposed a $1,000 sanction against Counsel and her firm. Counsel was ordered to serve the sanction order on her client and file proof of service. The court declined harsher penalties, crediting her swift admission, apology, and internal reforms.

Key Judicial Reasoning

The court found subjective bad faith due to the complete absence of verification. It cited a range of other AI-related sanction decisions, underscoring that even outsourcing to a “diligent and trusted” paralegal is not a defense when due diligence is absent.

Source: Volokh
Bandla v. Solicitors Regulation Authority UK (UK) 13 May 2025 Pro Se Litigant Google Search (Allegedly)
Fabricated Case Law (2)
Misrepresented Case Law (1), Legal Norm (2)
Application for extension of time refused; appeal struck out as abuse of process; indemnity costs of £24,727.20 ordered; permission to appeal denied 24727 GBP

AI Use

Bandla denied using AI, claiming instead to have relied on Google searches to locate “supportive” case law. He admitted that he did not verify any of the citations and never checked them against official sources. The court found this unacceptable, particularly from someone formerly admitted as a solicitor.

Hallucination Details

Bandla’s submissions cited at least 27 cases which the Solicitors Regulation Authority (SRA) could not locate.

Bandla maintained summaries and quotations from these cases in formal submissions. When pressed in court, he admitted having never read the judgments, let alone verified their existence.

Ruling/Sanction

The High Court refused the application for an extension of time, finding Bandla’s explanations inconsistent and unreliable. The court independently struck out the appeal on grounds of abuse of process due to the submission of fake authority. It imposed indemnity costs of £24,727.20. The judge emphasized that even after being alerted to the fictitious nature of the cases, Bandla neither withdrew nor corrected them.

Key Judicial Reasoning

The court found Bandla’s conduct deeply troubling, noting his previous experience as a solicitor and his professed commitment to legal standards. It held that the deliberate or grossly negligent inclusion of fake case law—especially in an attempt to challenge a disciplinary disbarment—was an abuse requiring strong institutional response.

Department of Justice v Wise Queensland Civil and Administrative Tribunal (Australia) 13 May 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
Misrepresented Case Law (1), Exhibits or Submissions (3), Legal Norm (2)
Warning

The second respondent, Carly Dakota Wise, a self-represented litigant, filed an application for the recusal of a tribunal member, alleging bias and procedural unfairness. The application was based on several grounds, including fabricated legal citations - despite Ms. Wise having been warned in interlocutory proceedings to check the authorities she relied on. The court cited the local Guidelines for the Use of Generative Artificial Intelligence (AI) Guidelines for Responsible Use by Non-Lawyers, available here, to stress that self-represented litigants need to check the accuracy of their pleadings.

Jamisson Roriz de Santana Andrade v. Tribunal Superior do Trabalho Supremo Tribunal Federal (Brazil) 12 May 2025 Lawyer Implied use of MobiOffice's AI Assistant
Fabricated Case Law (3)
False Quotes Legal Norm (1)
Misrepresented Case Law (1)
Case summarily dismissed; Counsel referred to the Bar Association; Claimant ordered to pay double the costs

AI Use

The petition’s pages were marked “Criado com MobiOffice.” The STF verified that MobiOffice includes a built-in AI writing assistant. Combined with the inclusion of fictitious citations, this led the Court to conclude that AI had been used and not reviewed. The judge characterized this as reckless conduct.

Hallucination Details

  • Claimed violations of STF precedents including RE 464.867/SP and RE 226.855/RS, which were either inapplicable or misrepresented
  • Claimed Súmula Vinculante 6 said something entirely false (its actual content concerns military service remuneration)
  • Cited judgments ARE 1.218.084 AgR and RE 328.111/DF as relevant when they were either misquoted or irrelevant
  • Court concluded these references were invented or misrepresented, “false statements intended to mislead”

Ruling/Sanction

  • Rejected the complaint as manifestly inadmissible
  • Found that counsel likely used AI and submitted the petition without review
  • Ordered notification to both the national and Bahia sections of the OAB
  • Declared the petitioner litigated in bad faith under Article 80, V, of the Brazilian Civil Procedure Code
  • Imposed a procedural penalty of double the initial court costs
  • Ordered referral to dívida ativa (federal collections) if not paid.
Newbern v. Desoto County School District et al. N.D. Mississippi (USA) 12 May 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Exhibits or Submissions (1), other (1)
Case dismissed, in part as a sanction for fabrication of legal authorities

AI Use

The court found that several of the cases cited by the plaintiff in her briefing opposing Officer Hill’s qualified immunity defense did not exist. Although Newbern suggested the citations may have been innocent mistakes, she did not challenge the finding of fabrication. No AI tool was admitted or named, but the structure and specificity of the invented cases strongly suggest generative AI use.

Hallucination Details

The fabricated authorities were not background references, but “key authorities” cited to establish that Hill’s alleged conduct violated clearly established law. The court observed that the fake cases initially appeared to be unusually on-point compared to the rest of plaintiff’s citations, which raised suspicion. Upon scrutiny, it confirmed they did not exist.

Ruling/Sanction

The court dismissed the federal claims against Officer Hill as a partial sanction for plaintiff’s fabrication of legal authority and failure to meet the burden under qualified immunity. However, it declined to dismiss the entire case, citing the interest of the minor child involved and the relevance of potential state law claims. It permitted discovery to proceed on those claims to determine whether Officer Hill acted with malice or engaged in other conduct falling outside the scope of Mississippi Tort Claims Act immunity.

Key Judicial Reasoning

The court found that plaintiff’s citation of fictitious cases undermined her effort to meet the demanding “clearly established” standard. It rejected her claim that the fabrication was an innocent mistake and viewed it in light of her broader litigation conduct, which included excessive filings and disregard for procedural limits.

Case No. 72079-11-24 Israel (Israel) 12 May 2025 Lawyer Unidentified
Fabricated Case Law (1)
No immediate sanction imposed; the matter was referred to the Legal Department of the Court Administration for review and potential action, including referral to the Ethics Committee of the Israel Bar Association

AI Use

Counsel explained that the hallucinated citations were included in a draft intended for personal legal research and learning, which was mistakenly filed with the court. This constituted an implicit admission that generative AI tools were involved.

Ruling/Sanction

While Judge Itay Katz did not impose personal costs, he referred the matter to the Legal Department of the Judicial Authority to determine whether further steps—including referral to the Israel Bar Association Ethics Committee—should be taken. The court emphasized this was done as a gesture of leniency with the hope that such behavior will not recur.

Key Judicial Reasoning

The court referred to several other recent Israeli cases to underscore the growing recognition of AI hallucination risk in legal practice. It reiterated the requirement for attorneys to meticulously verify any citation before submission and warned that future similar instances may not receive such lenient treatment.

Crypto Open Patent Alliance v. Wright (2) UK (UK) 12 May 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Misrepresented Case Law (1), Exhibits or Submissions (4), Legal Norm (2), other (2)
General Civil Restraint Order (GCRO) granted for 3 years; Case referred to Attorney General; Costs awarded to applicants. 100000 GBP

AI Use

Dr. Wright, after beginning to represent himself, repeatedly used AI engines (such as ChatGPT or similar) to generate legal documents. These documents were characterized by the court as "highly verbose and repetitious" and full of "legal nonsense". This use of AI contributed to filings containing numerous false references to authority and misrepresentations of existing law.

Hallucination Details

While the core issue in Dr. Wright's litigation was his fundamental dishonesty (claiming to be Satoshi Nakamoto based on "lies and ... elaborately forged documents" ), the use of AI introduced specific problems. His appeal documents, bearing signs of AI creation, contained "numerous false references to authority". His later submissions also involved "citation of non-existent authorities". This AI-driven production of flawed legal arguments formed part of his broader pattern of disrespect for court rules and process.

Ruling/Sanction

Mr Justice Mellor granted a General Civil Restraint Order (GCRO) against Dr. Wright for a three-year period. He found that an Extended CRO (ECRO) would be insufficient given the scope and persistence of Dr. Wright's abusive litigation. The court also referred Dr. Wright's conduct to the Attorney General for consideration of a civil proceedings order under s.42 of the Senior Courts Act 1981. Dr. Wright was ordered to pay the applicants' costs for the CRO application, summarily assessed at £100,000.

Key Judicial Reasoning

The court found "overwhelming" evidence that Dr. Wright had persistently brought claims that were Totally Without Merit (TWM), numbering far more than the required threshold. This conduct involved extensive lies and forgeries across multiple jurisdictions and targeted individuals who often lacked the resources to defend themselves. The judge concluded there was a "very significant risk" that Dr. Wright would continue this abusive conduct unless restrained. The court noted his consistent contempt for court rules and processes, including his perjury, forgery, breach of orders, and flawed submissions (including those using AI). A GCRO was deemed just and proportionate to protect both potential future litigants and the finite resources of the court system

Reclamação (RCL) 78.890 / BA Supremo Tribunal Federal (Brazil) 12 May 2025 Lawyer MobiOffice
Fabricated Case Law (3)
Misrepresented Case Law (1), Legal Norm (1)
Reclamação found manifestly unfounded; bad faith and monetary sanction (double court costs); OAB and OAB/BA to be notified 1

The STF relator found that the petition relied on decisions that could not be located and contained false statements about the content of Súmula Vinculante n.º 6 and other precedents. The petition bore a 'Criado com MobiOffice' watermark and the relator concluded the author likely used an AI writing assistant without review. The complaint was denied, bad faith was declared and procedural costs were doubled; OAB was notified.

Peter Gilmai v Abel Tol & Ors National Court of Justice at Lae (Papua New Guinea) 9 May 2025 Lawyer ChatGPT
Fabricated Case Law (4)
Referral to Public Solicitor and PNG Law Society; Order to show cause
In re Thomas Grant Neusom M.D. Florida (USA) 8 May 2025 Lawyer Unidentified Multiple fictitious or misrepresented case citations Suspension from practice before the Middle District of Florida for one year; immediate prohibition on accepting new federal matters; conditional reinstatement

(Grievance Committee Report available here.)

AI Use

Neusom told the grievance committee that he “may have used artificial intelligence” in preparing filings, and that any hallucinated cases were not deliberately fabricated but may have come from AI tools. The filings in question included a notice of removal and a motion for summary judgment. The judge later noted a pattern of citations inconsistent with established case law and unsupported by known databases.

Hallucination Details

Citations included cases that either did not exist or were grossly mischaracterized. Notably:

  • Southern Specialties, Inc. v. Pulido Produce, Inc. – no such case found in Westlaw, Lexis, or PACER
  • Trilogy Communications v. Times Fiber – cited in support of breach of contract when it was a patent matter involving no such principles

Neusom failed to produce the full texts of the cited cases when requested and instead filed a 721-page exhibit in violation of court orders.

Ruling/Sanction

The court adopted the grievance committee’s recommendation and imposed a one-year suspension. Neusom is prohibited from accepting new federal cases in the Middle District of Florida during the suspension and must:

  • Notify existing clients and the court of his suspension
  • File a compliance affidavit within 30 days
  • Complete appropriate CLE and counseling programs
  • Remain in good standing with the Florida Bar
  • Apply for reinstatement only after certifying compliance

Key Judicial Reasoning

The court found that Neusom violated Rules 4-1.3, 4-3.3(a)(3), 4-3.4(c), and 4-8.4(c) of the Florida Rules of Professional Conduct. His failure to verify AI-generated content, compounded by noncompliance with orders and false statements to opposing counsel, demonstrated a pattern of recklessness and dishonesty. The court emphasized that federal proceedings require a high standard of diligence and that invoking AI cannot excuse failure to meet professional obligations.

Israel v. Ibrahim Mahajneh Israel (Israel) 7 May 2025 Prosecutor Unidentified
Fabricated Legal Norm (1)
No sanction imposed; judge criticized the error as a “disgrace”; granted partial relief to applicant

AI Use

In opposing the return of a seized mobile phone, the prosecution cited a non-existent statutory provision allegedly defining what qualifies as an “institutional computer.” The judge identified the law as fictional and attributed its creation to generative AI, noting that it does not appear in any legal database or government source. The court referred to this as a product “created by artificial intelligence.”

Hallucination Details

The prosecution cited a statute regarding institutional computer definitions which, upon investigation, did not exist in Israeli law. The judge conducted internet and database searches to confirm its nonexistence. The judge criticized the error, remarking: “If I thought I had seen everything in 30 years on the bench, I was mistaken”

Ruling/Sanction

The judge declined to sanction the prosecution but strongly rebuked the conduct, calling it embarrassing and improper.

Key Judicial Reasoning

The judge stressed that citing phantom laws undermines public confidence and judicial efficiency. Even absent malice, reliance on fictitious AI-generated legal references is unacceptable. The judgment did not penalize the prosecution but underscored the need for due diligence and warned of reputational damage.

Matter of Raven Investigations & Security Consulting B-423447 GAO (USA) 7 May 2025 Pro Se Litigant Unidentified Multiple fabricated citations to prior GAO decisions Warning

AI Use

GAO requested clarification after identifying case citation irregularities. The protester confirmed that their representative was not a licensed attorney and had relied on a combination of public tools, AI-based platforms, and secondary summaries, which produced fabricated or misattributed citations.

Hallucination Details

Examples included:

  • GAO B-numbers with no corresponding decision
  • CPD citations that did not match the referenced holding
  • Alleged direct quotations not found in any GAO decision

The fabrications mirrored patterns typical of AI hallucinations.

Ruling/Sanction

Although the protest was dismissed on academic grounds, GAO addressed the citation misconduct. It did not impose sanctions in this case but warned that future submission of non-existent authority could lead to formal disciplinary action—including dismissal, cost orders, and bar referrals (in the case of attorneys).

Lacey v. State Farm General Insurance C.D. Cal (USA) 6 May 2025 Lawyer CoCounsel, Westlaw Precision, Google Gemini
Fabricated Case Law (2)
False Quotes Case Law (4)
Striking of briefs; denial of requested discovery relief; Large monetary sanctions jointly and severally against the two law firms 31100 USD

AI Use

Counsel used CoCounsel, Westlaw’s AI tools, and Google Gemini to generate a legal outline for a discovery-related supplemental brief. The outline contained hallucinated citations and quotations, which were incorporated into the filed brief by colleagues at both Ellis George and K&L Gates. No one verified the content before filing. After the Special Master flagged two issues, counsel refiled a revised brief—but it still included six AI-generated hallucinations and did not disclose AI use until ordered to respond.

Hallucination Details

At least two cases did not exist at all, including a fabricated quotation attributed to Booth v. Allstate Ins. Co., 198 Cal.App.3d 1357 (1989). Misquoted or fabricated quotes attributed to National Steel Products Co. v. Superior Court, 164 Cal.App.3d 476 (1985). Several additional misquotes and garbled citations across three submitted versions of the brief. Revised versions attempted to silently “fix” errors without disclosing their origin in AI output.

Ruling/Sanction

The Special Master (Judge Wilner) struck all versions of Plaintiff’s supplemental brief, denied the requested discovery relief, and imposed:

  • $26,100 in fees to reimburse Defendant for Special Master costs
  • $5,000 in additional attorney’s fees to Defendant
  • Total monetary sanction: $31,100, payable jointly and severally by Ellis George LLP and K&L Gates LLP
  • No sanctions against individual attorneys due to candid admissions and remedial action, but strong warning issued

Key Judicial Reasoning

The submission and re-submission of AI-generated material without verification, especially after warning signs were raised, was deemed reckless and improper. The court emphasized that undisclosed AI use that results in fabricated law undermines judicial integrity. While individual attorneys were spared, the firms were sanctioned for systemic failure in verification and supervision. The Special Master underscored that the materials nearly made it into a judicial order, calling that prospect “scary” and demanding “strong deterrence.”

Rotonde v. Stewart Title Insurance Co NY SC (USA) 6 May 2025 Pro Se Litigant Implied Several non-existent legal citations Motion to dismiss granted in full; no sanction imposed, but court formally warned plaintiff

AI Use

The court observed that “some of the cases that plaintiff cites… do not exist,” and noted it had “tried, in vain,” to find them. While no explicit AI use is admitted by the plaintiff, the pattern and specificity of the fabricated citations are characteristic of LLM-generated hallucinations.

Ruling/Sanction

The court dismissed all five causes of action—including negligence, tortious interference, aiding and abetting fraud, declaratory judgment, and breach of implied covenant of good faith and fair dealing—as either untimely or duplicative/deficient on the merits. It declined to impose sanctions but explicitly invoked Dowlah v. Professional Staff Congress, 227 AD3d 609 (1st Dept. 2024), and Will of Samuel, 82 Misc 3d 616 (Sur. Ct. 2024), to warn plaintiff that any future citation of fictitious cases would result in sanctions.

Key Judicial Reasoning

Justice Jamieson noted that while the court is “sensitive to plaintiff's pro se status,” that does not excuse disregard of procedural rules or the submission of fictitious citations. The court emphasized that its prior decision in related litigation in 2022 undermined plaintiff’s tolling claims, and that Executive Order extensions during the COVID-19 pandemic did not rescue otherwise-expired claims. The hallucinated citations failed to salvage plaintiff’s fraud and tolling theories, and their use was treated as an aggravating—though not yet sanctionable—factor.

X v. Board of Trustees of Governors State University N.D. Illinois (USA) 6 May 2025 Pro Se Litigant Implied One fabricated citation Warning

"For that principal [sic] [X] cites a case, Gunn v. McKinney, 259 F.3d 824, 829 (7th Cir. 2001), which neither defense counsel nor the Court has been able to locate. The Court reminds [X] that Federal Rule of Civil Procedure 11 applies to pro se litigants, and sanctions may result from such conduct, especially if the citation to Gunn was not merely a typographical or citation error but instead referred to a non-existent case. By presenting a pleading, written motion, or other paper to the Court, an unrepresented party acknowledges they will be held responsible for its contents. See Fed. R. Civ. P. 11(b)."

Harris v. Take-Two Interactive Software D. Colorado (USA) 6 May 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Warning

Court held that: "The use of fictitious quotes or cases in filings may subject a party, including a pro se party, to sanctions pursuant to Federal Rule of Civil Procedure 11 as “pro se litigants are subject to Rule 11 just as attorneys are.”

Flowz Digital v. Caroline Dalal C.D. Cal (USA) 5 May 2025 Lawyer Lexis+AI
Fabricated Case Law (1)
Misrepresented Case Law (2)
Order to show cause

In their Response to the Order to show Cause, Counsel specified that they used Lexis+AI, and stressed that "LexisNexis itself has publicly emphasized the reliability of its Lexis+ AI platform, marketing it as providing “hallucination-free legal citations” specifically to avoid citation errors."
Case was eventually jointly dismissed.

Wilt v. Department of the Navy E.D. Texas (USA) 2 May 2025 Pro Se Litigant Unidentified
Fabricated Case Law (2)
Warning
Source: Jesse Schaefer
Lozano González v. Roberge Housing Administrative Tribunal (Canada) 1 May 2025 Pro Se Litigant ChatGPT
False Quotes Legal Norm (1)

The landlord sought to repossess a rental property, claiming the lease renewal was suspended based on a misinterpretation of Quebec's civil code articles. He used ChatGPT to translate these articles, which resulted in a completely different meaning. The Tribunal found the repossession request invalid as it was based on a date prior to the lease's end. The Tribunal rejected the claim of abuse, accepting the landlord's sincere belief in his misinterpretation, influenced by AI translation, and noted his language barrier and residence in Mexico. The Tribunal advised the landlord to seek reliable legal advice in the future.

Gustafson v. Amazon.com D. Arizona (USA) 30 April 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Exhibits or Submissions (1)
Warning
Moales v. Land Rover Cherry Hill D. Connecticut (USA) 30 April 2025 Pro Se Litigant Unidentified
Misrepresented Case Law (1), Legal Norm (4)
Plaintiff warned to ensure accuracy of future submissions

AI Use

The court stated that “Moales may have used artificial intelligence in drafting his submissions,” citing widespread concerns over AI hallucination. It noted that several citations in his complaint and show-cause response were plainly incorrect or irrelevant. While Moales did not admit AI use, the court cited Strong v. Rushmore Loan Mgmt. Servs., 2025 WL 100904 (D. Neb.) and Mata v. Avianca to contextualize its concern.

Hallucination Details

Cited Ernst & Ernst v. Hochfelder, 425 U.S. 185 (1976), and S.E.C. v. W.J. Howey Co., 328 U.S. 293 (1946) as supporting the existence of a federal common law fiduciary duty—an inaccurate legal proposition. The court characterized such misuses as “the norm rather than the exception” in Moales’s submissions. It stopped short of identifying all misused authorities but made clear that the inaccuracies were pervasive.

Ruling/Sanction

The complaint was dismissed for lack of subject matter jurisdiction under Rule 12(h)(3). Moales was permitted to file an amended complaint by May 28, 2025, but was warned that future filings must be factually and legally accurate. The court declined to reach the venue issue or impose immediate sanctions but warned Moales that misrepresentation of law may violate Rule 11.

Key Judicial Reasoning

The court found no basis for federal question jurisdiction and rejected Moales’s reliance on the Declaratory Judgment Act, constructive trust theories, and a nonexistent “federal common law of securities.” It also held that Moales failed to plausibly allege the amount in controversy necessary for diversity jurisdiction.

Nexgen Pathology Services Ltd v. Darcueil Duncan (Trinidad & Tobago) 30 April 2025 Lawyer Implied
Fabricated Case Law (6)
Misrepresented Case Law (1)
Court referred the matter to the Disciplinary Committee

AI Use

Counsel denied using AI directly and attributed the hallucinations to “Google and Google Scholar” searches by a junior research assistant. However, the court found the citation pattern highly characteristic of generative AI hallucinations, including plausible-sounding but non-existent authority names and improper formatting. Counsel acknowledged a lack of adequate supervision and admitted that the cited authorities were never verified nor included in the bundle.

Hallucination Details

Seven cited authorities were found to be fictitious or mischaracterized, including:

  • BWIA v. Ramnarine (TT Industrial Court, 2005)
  • National Petroleum Marketing Co. v. Brewster (TT 2007)
  • Horner v. KMW [2000] IRLR 814
  • Jones v. Manchester Corporation [1952] 2 QB 852 (used for unrelated point)
  • London School of Economics v. Dr Don [2016] EAT
  • Ishmael v. NIPDEC (TT, 2014)
  • BWIA v. Hollis (TT, 2001)

These were used to support the implied obligation to repay employer-sponsored training, the core issue of the case. None were available in legal databases or official archives, and no hard copies were ever submitted.

Ruling/Sanction

While the court awarded judgment for the Claimant on the breach of contract claim, it found the citation misconduct egregious and referred the matter to the Disciplinary Committee of the Law Association. The Court noted that hallucinated citations undermine judicial integrity and must be proactively prevented.

Key Judicial Reasoning

Justice Westmin James emphasized that lawyers must not submit unverifiable or fictitious authority, whether generated by AI or not. He underscored that the legal system depends on the accuracy of submissions, and that even unintentional use of hallucinated material violates the duty of candour and may constitute professional misconduct.

Anonymous v. Anonymous Israel (Israel) 29 April 2025 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Exhibits or Submissions (1)
Petition dismissed in limine; Plaintiff’s counsel ordered to pay ₪1,500 in personal costs to the state and ₪3,500 to the opposing party 5000 ILS

AI Use

The plaintiff’s attorney denied deliberate use of generative AI, claiming the wrong file numbers were inserted by mistake. The court rejected this explanation, finding the hallucinated decisions did not exist in any legal archive and could not plausibly arise from mere misnumbering. The court accepted the defendant’s assertion that the fabricated citations originated from generative AI.

Hallucination Details

Out of five rulings cited in the petition, three were not found in any legal database. Two additional cases were filed after the hearing, but neither matched the original citations or contained the propositions advanced in the pleading. The court found the overall drafting pattern aligned with generative AI hallucination phenomena.

Ruling/Sanction

Judge Merav Eliyahu dismissed the petition and imposed personal costs of ₪1,500 against Plaintiff’s counsel (payable to the state) and ₪3,500 (payable to the opposing party). She cited Supreme Court precedent and ethical commentary emphasizing the risks of hallucinated legal drafting. She emphasized that lawyers must not rely blindly on AI tools and must always verify the authenticity of legal authorities cited in pleadings.

Key Judicial Reasoning

The judge found that legal pleadings are the “foundational documents of judicial proceedings” and must be “accurate, reliable, and competently drafted.” Submitting fictitious judgments constitutes not only a procedural abuse but an ethical breach. Even absent bad faith, failure to verify AI-generated legal content breaches a lawyer’s core obligations.

Beschluss v. 29.04.2025 OLG Celle (Germany) 29 April 2025 Lawyer Implied
Fabricated Case Law (4)
Court treated the cited authorities as Fehlzitate (not verifiable) and did not rely on them
Willis v. U.S. Bank National Association as Trustee, Igloo Series Trust N.D. Texas, Dallas Division (USA) 28 April 2025 Pro Se Litigant Implied Fabricated citation(s) Warning
Source: Jesse Schaefer
Simpson v. Hung Long Enterprises Inc. B.C. Civil Resolution Tribunal (Canada) 25 April 2025 Pro Se Litigant Unidentified
Fabricated Case Law (4)
Misrepresented Legal Norm (1)
Other side compensated for time spent through costs order (500 CAD)

"Ms. Simpson referred to a non-existent CRT case to support a patently incorrect legal position. She also referred to three Supreme Court of Canada cases that do not exist. Her submissions go on to explain in detail what legal principles those non-existent cases stand for. Despite these deficiencies, the submissions are written in a convincingly legal tone. Simply put, they read like a lawyer wrote them even though the underlying legal analysis is often wrong. These are all common features of submissions generated by artificial intelligence." [...]

"25. I agree with Hung Long that there are two extraordinary circumstances here that justify compensation for its time. The first is Ms. Simpson’s use of artificial intelligence. It takes little time to have a large language model create lengthy submissions with many case citations. It takes considerably more effort for the other party to wade through those submissions to determine which cases are real, and for those that are, whether they actually say what Ms. Simpson purported they did. Hung Long’s owner clearly struggled to understand Ms. Simpson’s submissions, and his legal research to try to understand them was an utter waste of his time. I reiterate my point above that Ms. Simpson’s submissions cited a non-existent case in support of a legal position that is the precise opposite of the existing law. This underscores the impact on Hung Long. How can a self-represented party respond to a seemingly convincing legal argument that is based on a case it is impossible to find?

26. I am mindful that Ms. Simpson is not a lawyer and that legal research is challenging. That said, she is responsible for the information she provides the CRT. I find it manifestly unfair that the burden of Ms. Simpson’s use of artificial intelligence should fall to Hung Long’s owner, who tried his best to understand submissions that were not capable of being understood. While I accept that Ms. Simpson did not knowingly provide fake cases or misleading submissions, she was reckless about their accuracy."

Benjamin v. Costco Wholesale Corp E.D.N.Y. (USA) 24 April 2025 Lawyer ChatOn Five fabricated case citations, and quotations Monetary sanction; public reprimand; order to serve client with decision; no disciplinary referral due to candor and remediation 1000 USD

AI Use

Counsel used ChatOn to rewrite a reply brief with case law, under time pressure, without verifying the outputs. The five cases did not exist; citations were entirely fictional. Counsel later admitted this in a sworn declaration and at hearing, describing her actions as a lapse caused by workload and inexperience with AI.

Hallucination Details

Fabricated cases included:

  • Klein v. E.I. Du Pont de Nemours & Co., 406 F.2d 1004 (cited case does not exist)
  • Gordon v. N.Y. Cent. R.R. Co., 202 F. Supp. 2d 290
  • Mitchell v. JCG Industries, 2010 WL 11627832
  • Hollander v. Sweeney, 2005 WL 19904045
  • Davis v. S. Farm Bureau Cas. Ins. Co., 2019 WL 3452601

None of these cases matched any legal source. Counsel filed them as part of a sworn statement under penalty of perjury.

Ruling/Sanction

The court imposed a $1,000 sanction payable to the Clerk; ordered the counsel to serve the order on her client and file proof of service. The court acknowledged her sincere remorse and remedial CLE activity, but emphasized the seriousness of submitting hallucinated cases under oath. Sanctions were tailored for deterrence, not punishment.

Key Judicial Reasoning

Quoting Park v. Kim and Mata v. Avianca, the court held that submitting legal claims based on nonexistent authorities without checking them constitutes subjective bad faith. Signing a sworn filing without knowledge of its truth is independently sanctionable. Time pressure is not a defense. Lawyers cannot outsource core duties to generative AI and disclaim responsibility for the results.

Nichols v. Walmart S.D. Georgia (USA) 23 April 2025 Pro Se Litigant Implied Multiple fictitious legal citations Case dismissed for lack of subject matter jurisdiction and as a Rule 11 sanction for bad-faith submission of fabricated legal authorities

AI Use

Plaintiff submitted a motion to disqualify opposing counsel that cited multiple non-existent cases. She offered no clarification about how the citations were obtained or whether she had attempted to verify them. The court noted this failure and declined to excuse the misconduct, though it stopped short of attributing it directly to AI tools.

Hallucination Details

The court reviewed Plaintiff’s motion and found that some of the cited cases did not exist. Despite being ordered to show cause, Plaintiff responded only with general statements about her good faith and complaints about perceived procedural unfairness, without addressing the origin or verification of the fake cases.

Ruling/Sanction

The court dismissed the case for lack of subject matter jurisdiction and independently dismissed it as a sanction for bad-faith litigation under Rule 11. It found Plaintiff’s conduct—submitting fictitious legal authorities and refusing to take responsibility for them—warranted dismissal, even if monetary sanctions were not appropriate. The court cited Mata v. Avianca, Morgan v. Community Against Violence, and O’Brien v. Flick as relevant precedents affirming the sanctionability of hallucinated case law.

Key Judicial Reasoning

Judge Hall held that Plaintiff’s conduct went beyond excusable error. Her submission of fabricated cases, refusal to explain their origin, and attempts to shift blame to perceived procedural grievances demonstrated bad faith. The court concluded that dismissal—though duplicative of the jurisdictional ground—was warranted as a standalone sanction to deter future abuse by similarly situated litigants.

Brown v. Patel et al. S.D. Texas (USA) 22 April 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
Misrepresented Case Law (2)
Warning

Although no immediate sanctions were imposed, Magistrate Judge Ho explicitly warned Plaintiff that future misconduct of this nature may violate Rule 11 and lead to consequences.

Rowe v National Australia Bank Ltd South Australia (Australia) 17 April 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Ferris v. Amazon.com Services N.D. Mississippi (USA) 16 April 2025 Pro Se Litigant ChatGPT 7 fictitious cases Plaintiff ordered to pay Defendant’s reasonable costs related to addressing the fabricated citations

AI Use

Mr. Ferris admitted at the April 8, 2025 hearing that he used ChatGPT to generate the legal content of his filings and even the statement he read aloud in court. The filings included at least seven entirely fictitious case citations. The court noted the imbalance: it takes a click to generate AI content but substantial time and labor for courts and opposing counsel to uncover the fabrications.

Hallucination Details

The hallucinated cases included federal circuit and district court decisions, complete with plausible citations and jurisdictional diversity, crafted to lend credibility to Plaintiff’s intellectual property and employment-related claims. These false authorities were submitted both in the complaint and in opposition to Amazon’s motion to dismiss.

Ruling/Sanction

The court found a Rule 11 violation and, while initially inclined to dismiss the case outright, chose instead to impose a compensatory monetary sanction. Amazon is entitled to submit a detailed affidavit of costs directly attributable to rebutting the false citations. The final monetary amount will be set in a subsequent order.

Key Judicial Reasoning

Judge Michael P. Mills condemned the misuse of generative AI as a serious threat to judicial integrity. Quoting Kafka (“The lie made into the rule of the world”), the court lamented the rise of “a post-truth world” and framed Ferris as an “avatar” of that dynamic. Nevertheless, it opted for the least severe sanction consistent with deterrence and fairness: compensatory costs under Rule 11.

Sims v. Souily-Lefave D. Nevada (USA) 15 April 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Crystal Truong, et al. v. Flint Hills Resources, LLC, et al. S.D. Texas (USA) 14 April 2025 Lawyer ChatGPT Fabricated citation(s), misrepresented precedents Show cause order; CLE commitment

After explaining what happened (document) counsel opted to non-suit all remaining claims, which means that the court never ruled on the show cause proceedings.

Vilmar Martins dos Santos v. State of Parana Parana State (Brazil) 11 April 2025 Lawyer Implied
Fabricated Case Law (9)
False Quotes Exhibits or Submissions (2)
Misrepresented Case Law (2)
Appeal dismissed; lawyers warned
Bevins v. Colgate-Palmolive Co. E.D. Pa. (USA) 10 April 2025 Lawyer Unidentified
Fabricated Case Law (2)
Striking of Counsel’s Appearance + Referral to Bar Authorities + Client Notification Order

AI Use

Counsel filed opposition briefs citing two nonexistent cases. The court suspected generative AI use based on "hallucination" patterns but Counsel neither admitted nor explained the citations satisfactorily. Failure to comply with a standing AI order aggravated sanctions.

Hallucination Details

Two fake cases cited. Citation numbers and Westlaw references pointed to irrelevant or unrelated cases. No affidavit or real case documents were produced when ordered.

Ruling/Sanction

Counsel's appearance was struck with prejudice. The Court ordered notification to the State Bar of Pennsylvania and the Eastern District Bar. Consel was required to inform his client, Bevins, of the sanctions and the need for new counsel if re-filing.

Bischoff v. South Carolina Department of Education Admin Law Court, S.C. (USA) 10 April 2025 Pro Se Litigant Implied Fake citations Warning

The court held that: "It is likely that Appellant employed argument generated by an artificial intelligence (AI) program which contained the fictitious case citation and cautions Appellant that many harms flow from the use of non-existent case citations and fake legal authority generated by AI programs, including but not limited to the waste of judicial resources and time and waste of resources and time of the opposing party. Were courts to unknowingly rely upon fictitious citations, citizens and future litigants might question the validity of court decisions and the reputation of judges. If, alternatively, Appellant's use of a fictitious case was not the result of using an AI program, but was instead a conscious act of the Appellant, Appellant's action could be deemed a fraud on the Court. Appellant is hereby expressly warned that submission of fictitious case authorities may subject Appellant to sanctions under the S.C. Frivolous Proceedings Act, S.C. Code Ann. § 15-36-10(Supp. 2024)."

Shekartz v. Assuta Ashdod Ltd Israel (Israel) 7 April 2025 Lawyer Implied 25 fake citations Monetary sanction 7000 ILS
Ayinde v. Borough of Haringey High Court (UK) 3 April 2025 Lawyer Unidentified
Fabricated Case Law (5)
Misrepresented Legal Norm (1)
Wasted costs order; Partial disallowance of Claimant’s costs; Order to send transcript to Bar Standards Board and Solicitors Regulation Authority 11000 GBP

AI Use

The judgment states that the only other explanation for the fabricated cases was the use of artificial intelligence.

Hallucination Details

The following five nonexistent cases were cited:

  • R (El Gendi) v Camden [2020] EWHC 2435 (Admin)
  • R (Ibrahim) v Waltham Forest [2019] EWHC 1873
  • R (H) v Ealing [2021] EWHC 939 (Admin)
  • R (KN) v Barnet [2020] EWHC 1066 (Admin)
  • R (Balogun) v Lambeth [2020] EWCA Civ. 1442

Ruling/Sanction

The court imposed wasted costs orders against both barrister and solicitor, reduced the claimant’s recoverable costs, and ordered the judgment to be provided to the BSB and SRA.

Daniel Jaiyong An v. Archblock, Inc. Delaware Chancery (USA) 3 April 2025 Pro Se Litigant Implied
False Quotes Case Law (2)
Misrepresented Case Law (2)
Motion denied with prejudice; no immediate sanction imposed, but petitioner formally warned and subject to future certification and sanctions

AI Use

The petitioner submitted a motion to compel discovery that contained several fabricated or misleading citations. The court explicitly stated that the motion bore hallmarks of generative AI use and referenced ChatGPT’s known risk of “hallucinations.” Although the petitioner did not admit AI use, the court found the origin clear and required future filings to include a GenAI usage certification.

Hallucination Details

Examples included:

  • Terramar Retail Centers, LLC v. Marion #2-Seaport Trust – cited for discovery principles it did not contain
  • Deutsch v. ZST Digital Networks, Inc. – quoted for a sentence not found in the opinion
  • Production Resources Group, LLC v. NCT Group, Inc. – attributed with a quote that appears nowhere in the case or legal databases

Court verified via Westlaw that some phrases returned only the petitioner’s motion as a result.

Ruling/Sanction

Motion to compel denied with prejudice. No immediate monetary sanction imposed, but petitioner was warned that further submission of fabricated authority may result in sanctions including monetary penalties or dismissal. Future filings must include a certification regarding the use of generative AI.

Key Judicial Reasoning

The Vice Chancellor emphasized that GenAI can benefit courts and litigants, but careless use that results in fictitious legal authorities wastes resources and harms judicial integrity.

Zzaman v. HMRC (UK) 3 April 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Misrepresented Case Law (7), Legal Norm (2)
Warning

Plaintiff had disclosed the use of AI in preparing his statement of case. The court noted:

"29. However, our conclusion was that Mr Zzaman’s statement of case, written with the assistance of AI, did not provide grounds for allowing his appeal. Although some of the case citations in Mr Zzaman’s statement were inaccurate, the use of AI did not appear to have led to the citing of fictitious cases (in contrast to what had happened in Felicity Harber v HMRC [2023] UKFTT 1007 (TC)). But our conclusion was that the cases cited did not provide authority for the propositions that were advanced. This highlights the dangers of reliance on AI tools without human checks to confirm that assertions the tool is generating are accurate.

Litigants using AI tools for legal research would be well advised to check carefully what it produces and any authorities that are referenced. These tools may not have access to the authorities required to produce an accurate answer, may not fully “understand” what is being asked or may miss relevant materials. When this happens, AI tools may produce an answer that seems plausible, but which is not accurate. These tools may create fake authorities (as seemed to be the case in Harber) or use the names of cases to which it does have access but which are not relevant to the answer being sought (as was the case in this appeal).

There is no reliable way to stop this, but the dangers can be reduced by the use of clear prompts, asking the tool to cite specific paragraphs of authorities (so that it is easy to check if the paragraphs support the argument advanced), checking to see the tool has access to live internet data, asking the tool not to provide an answer if it is not sure and asking the tool for information on the shortcomings of the case being advanced. Otherwise there is a significant danger that the use of an AI tool may lead to material being put before the court that serves no one well, since it raises the expectations of litigants and wastes the court’s time and that of opposing parties."

Bangholme Investments Pty Ltd v Greater Dandenong CC Victorian CAT (Australia) 3 April 2025 Pro Se Litigant Unidentified
Misrepresented Legal Norm (1)

Alan Hood relied on an AI search that inferred the Council was required to notify objectors. The Tribunal found that inference 'plainly incorrect', noting Hood had received the requisite notice and should have read the documents; the Tribunal nevertheless exercised discretion to join him.

Dehghani v. Castro New Mexico DC (USA) 2 April 2025 Lawyer Unidentified
Fabricated Case Law (6)
False Quotes Case Law (1)
Monetary sanction; required CLE on legal ethics and AI; mandatory self-reporting to NM and TX state bars; report of subcontractor to NY state bar; required notification to LAWCLERK 1500 USD

AI Use

Counsel hired a freelance attorney through LAWCLERK to prepare a filing. He made minimal edits and admitted not verifying any of the case law before signing. The filing included multiple fabricated cases and misquoted others. The court concluded these were AI hallucinations, likely produced by ChatGPT or similar.

Hallucination Details

Examples of non-existent cases cited include:

Moncada v. Ruiz, Vega-Mendoza v. Homeland Security, Morales v. ICE Field Office Director, Meza v. United States Attorney General, Hernandez v. Sessions, and Ramirez v. DHS.

All were either entirely fictitious or misquoted real decisions.

Ruling/Sanction

The Court sanctioned Counsel by:

  • Ordering a $1,500 fine
  • Requiring a 1-hour CLE on AI/legal ethics
  • Ordering him to self-report to the New Mexico and Texas bars
  • Ordering him to report the freelance lawyer to the New York bar
  • Requiring notification of LAWCLERK
  • Requiring proof of compliance by May 15, 2025

Key Judicial Reasoning

The court emphasized that counsel’s failure to verify cited cases, coupled with blind reliance on subcontracted work, constituted a violation of Rule 11(b)(2). The court analogized to other AI-sanctions cases. While the fine was modest, the court imposed significant procedural obligations to ensure deterrence.

Mazurek et al. v. Thomazoni Parana State (Brazil) 2 April 2025 Lawyer ChatGPT
Fabricated Case Law (3)
Referral to the bar; Monetary fine (1% of case value)
D'Angelo v. Vaught Illinois (USA) 2 April 2025 Lawyer Archie (Smokeball) Fabricated citation Monetary sanction 2000 USD
Boggess v. Chamness E.D. Texas (USA) 1 April 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Argument ignored
Source: Jesse Schaefer
Sanders v. United States Fed. claims court (USA) 31 March 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
Misrepresented Case Law (1), Legal Norm (1)
Warning

AI Use

The plaintiff did not admit to using AI, but the court inferred likely use due to the submission of fabricated citations matching the structure and behavior typical of generative AI hallucinations. The decision referenced public concerns about AI misuse and cited specific examples of federal cases where similar misconduct occurred.

Hallucination Details

Plaintiff cited:

  • Tucker v. United States, 24 Cl. Ct. 536 (1991) – does not exist
  • Fargo v. United States, 184 F.3d 1096 (Fed. Cir. 1999) – fabricated citation pointing to an unrelated Ninth Circuit case
  • Bristol Bay Native Corporation v. United States, 87 Fed. Cl. 122 (2009) – fictional
  • Quantum Construction, Inc. v. United States, 54 Fed. Cl. 432 (2002) – nonexistent
  • Hunt Building Co., LLC v. United States, 61 Fed. Cl. 243 (2004) – real case misused; contains no mention of unjust enrichment

Ruling/Sanction

The court granted the government’s motion to dismiss for lack of subject matter jurisdiction under Rule 12(b)(1). Although the court found a clear Rule 11 violation, it opted not to sanction the plaintiff, citing the evolving context of AI use and the absence of bad faith. A formal warning was issued, with notice that future hallucinated filings may trigger sanctions.

Key Judicial Reasoning

Judge Roumel noted that plaintiff’s attempt to rely on fictional case law was a misuse of judicial resources and a disservice to her own advocacy. The court cited multiple precedents addressing hallucinated citations and AI misuse, stating clearly that while leeway is granted to pro se litigants, the line is crossed when filings rely on fictitious law.

McKeown v. Paycom Payroll LLC W.D. Oklahoma (USA) 31 March 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Submission stricken out, and warning

AI Use

Although AI was not named and Plaintiff denied intentional fabrication, the court considered the citation (Adamov, 779 F.3d 851, 860 (8th Cir. 2015)) to be plainly fictitious. It noted the possibility that Plaintiff used generative AI tools, given the fabricated citation's plausible-sounding structure and mismatch with existing precedent.

Hallucination Details

Plaintiff submitted fabricated legal authorities in at least two filings, despite being explicitly warned by the court after the first incident. The false case cited in her sur-reply could not be located in any legal database. When asked to produce it, she responded that she had likely “garbled” the citation but provided no plausible alternative or correction.

Ruling/Sanction

The court declined to dismiss the action as a sanction, citing the limitations pro se litigants face in accessing reliable legal research tools. However, it granted the defendant’s motion to strike Plaintiff’s two unauthorized sur-replies and formally warned her that further violations of Rule 11 would lead to sanctions, including monetary penalties, filing restrictions, or dismissal.

SQBox Solutions Ltd. v. Oak BC Civil Resolution Tribunal (Canada) 31 March 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Legal Norm (2)
Misrepresented Case Law (4)
Litigant lost on merits

"By relying on inaccurate and false AI submissions, Mr. Oak hurts his own case. I understand that Mr. Oak himself might not be aware that the submissions are misleading, but they are his submissions and he is responsible for them. "

Source: Steve Finlay