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 (831 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 have any questions about the database, a FAQ is available here.
And 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.

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Last updated: 5 May 2026
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)
Turner v. Garrels CA Iowa (USA) 4 September 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Source: Jesse Schaefer
Re X Corp. BC Civil Resolution Tribunal (Canada) 4 September 2025 Pro Se Litigant Unidentified
False Quotes Case Law (1)
Misrepresented Case Law (1)
Claim for compensation dismissed due to false and misleading AI-assisted submissions
Source: Steve Finlay
April Ann Nelson v. Navient Solutions, LLC, et al. S.D. Iowa (USA) 4 September 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Warning
Source: Jesse Schaefer
Jason Stanford v. Behrooz P. Vida, et al. W.D. Texas (USA) 4 September 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
False Quotes Case Law (2)

The magistrate judge found multiple cited authorities in the plaintiff's complaint to be fabricated or misquoted: two cases could not be located and two quotations attributed to real cases did not appear in those opinions. The court warned the plaintiff and ordered him to provide copies of cited cases in future filings; recommended dismissal of federal claims and possible sanctions for continued misrepresentations.

Lockwood v. ICBC BC Civil Resolution Tribunal (Canada) 3 September 2025 Pro Se Litigant Implied
Fabricated Legal Norm (2)
Argument ignored
Pete v. Houston Methodist Hospital E.D. Texas (USA) 3 September 2025 Pro Se Litigant Unidentified
Fabricated Case Law (2), other (1)
Misrepresented other (1)
Order to show cause

Plaintiff admitted using AI to prepare filings, submitted an unsigned affidavit for a purported attorney and cited cases the court could not locate; court found false statements and potential fake caselaw and ordered show-cause re: Rule 11 sanctions and evidentiary hearing.

Steven E. Hobbs, Sr. v. Igor Goncharko, et al. N.D. Illinois (USA) 3 September 2025 Pro Se Litigant implied
Fabricated Case Law (1)
No sanction imposed, but noted Rule 11 may apply to pro se litigants.
Mark Khoury v Nira Kooij Supreme Court of Queensland (Australia) 3 September 2025 Pro Se Litigant implied
Fabricated Case Law (2)
Misrepresented Case Law (1), Legal Norm (1)
Application dismissed 1
XAI v XAH and another matter Family Court (Singapore) 3 September 2025 Pro Se Litigant ChatGPT
Fabricated Case Law (14)
Outdated Advice Repealed Law (1)
Order to pay costs; Required written declaration of generative AI use 1000 SGD

Father admitted using ChatGPT to generate case citations; 14 cited cases were non-existent or misattributed. Court treated them as AI hallucinations, disregarded them, awarded costs, and ordered declarations for future AI use.

Nixon v. Ken Ganley Ford West N.D. Ohio (USA) 3 September 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Warning
Givati et al. v. Peri Magistrate's Court Jaffa (Israel) 31 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Corrections to filings ordered
IBS Government Services, Inc. GAO (USA) 29 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Warning
Source: David Timm
Lothamer Tax Resolution, Inc. v. Paul Kimmel (1) W.D. Michigan (USA) 29 August 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Warning
Stewart v Good Shepherd Victoria CA (Australia) 29 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Gribble v Essential Energy NSW D.C. (Australia) 29 August 2025 Pro Se Litigant Unidentified
Fabricated Case Law (2)
Plaintiff ordered to exclude all Gen AI material
Cunningham v healthAlliance NZ Limited Employment Court (New Zealand) 29 August 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Warning
Alana Kotler v Ontario Secondary School Teachers’ Federation Ontario Labour Relations Board (Canada) 29 August 2025 Pro Se Litigant Implied
Fabricated Case Law (14)
Misrepresented Case Law (1)
Arguments ignored

The applicant relied on numerous case citations that the Board and OSSTF could not locate as cited; one located decision did not support the proposition relied upon. Applicant acknowledged possible citation errors and was asked to provide copies but objected. The Board refused to rely on unlocatable authorities and dismissed the application.

Lonnie Allbaugh v. University of Scranton M.D. Pennsylvania (USA) 28 August 2025 Pro Se Litigant Unidentified
Fabricated Case Law (2)
Monetary sanction; complaint dismissed without prejudice; leave to amend granted. 1000 USD

The court later declined to reconsider its sanction (see here).

Source: Robert Freund
Myers v. Tarion Warranty Corporation Ontario (Canada) 28 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Arguments ignored
USA v. Sethi E.D. Texas (USA) 28 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1), Exhibits or Submissions (1)
False Quotes Case Law (2)
Court denied defendant's motions; sentencing ordered to proceed as scheduled; no professional sanctions imposed.
United States v. Michael Shane DeBaere (1) W.D. Virginia (USA) 27 August 2025 Pro Se Litigant Implied
Fabricated Case Law (3), Doctrinal Work (1)
Warning
Takefman v. The Pickleball Club, LLC Third District Court of Appeal, State of Florida (USA) 27 August 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Misrepresented Case Law (1)
Order to show cause

" Opposing counsel, and the court, should not have to parse case citations and parentheticals to discern whether cases exist, and if so, if they stand for the propositions asserted. "

Helgen Industries GAO (USA) 26 August 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
Warning
Source: David Timm
MacEachern-Flatt v. University Health Network HRT Ontario (Canada) 25 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Babbar v. Tarion Warranty Corporation LAT Ontario (Canada) 25 August 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Source: Courtready
In re Mascio D. Colorado (Bankruptcy) (USA) 22 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Source: Jesse Schaefer
The Meniscus Trust v Chief Commissioner of State Revenue NSW (Australia) 21 August 2025 Pro Se Litigant Google Gemini; ChatGPT Use of generative AI in submissions resulting in unverified legal citations Arguments produced by AI given lesser weight

The self-represented Applicant admitted using generative AI (Google Gemini and ChatGPT) to prepare submissions. NCAT Procedural Direction 7 requires verification of citations when Gen AI is used; the Applicant did not verify citations. The Tribunal accepted the submissions into the record but placed greater weight on primary records and noted non-compliance with the verification requirement.

JML Rose Pty Ltd v Jorgensen (No 3) Federal Court of Australia (Australia) 19 August 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1), Legal Norm (1)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Outdated Advice Repealed Law (1)
N/A

""101    The use of AI technology in the Courts has been the subject of judicial observations, particularly regarding legal practitioners who are subject to professional and ethical obligations and responsibilities. However, as Bell CJ observed in May v Costaras [2025] NSWCA 178 at [15], with whom Payne JA and McHugh JA agreed, in the context of considering the use of AI in the preparation of submissions, that “(a)ll litigants are under a duty not to misled the court or their opponent.” The reliance on unverified materials produced by generative AI does have the potential to misled the Court.

102    Although the termed used in relation to erroneously generated references by AI is “hallucinations”, this is a term which seeks to legitimise the use of AI. More properly, such erroneously generated references are simply fabricated, fictional, false, fake and as such could be misleading.

103    All persons appearing before the Court have a duty to verify that the case law and legislation referred to and relied on, is accurate and that such materials actually exist. The references in Ayinde at [85] and [86] and in Costaras at [14]-[15], to matters involving litigants who are acting in person who rely on AI generated material clearly supports the position that all are required to verify the submissions made to the Court. There are many publicly available legal research websites, some which are accessible without a fee. Further, and without attempting to be exhaustive, the Queensland Supreme Court library is open and available to the public.

104    The use of generative AI to prepare submissions that may include fake authorities will nearly always introduce added costs, complexity and add to the burden of other parties and to the Court: Costaras at [16] and [49]. I gratefully adopt the observation from Ayinde at [9] that “(t)here are serious implications for the administration of justice and public confidence in the justice system if artificial intelligence is misused.” The Court in Ayinde observed from [10] to [31] the existing guidance, regulatory duties of the profession, referrals and the Court’s powers. Matters which are within the Court’s own domain include in the most serious of cases contempt of Court. The observations in Ayinde at [26]-[28] regarding contempt of court are not limited to legal practitioners.

105    As the reasons above demonstrate, the circumstances of this case involved many fake authorities, fabricated quotes and false propositions. It is unhelpful for the Court to be referred to, and for parties to rely on, such matters."

Lahti v. Consensys Software Inc. S.D. Ohio (USA) 19 August 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Misrepresented Case Law (1)
Submission Stricken

"The case at bar epitomizes the concern. Inordinate judicial resources were expended on reviewing cases cited by Plaintiff that did not exist. No doubt Plaintiff’s opponent in this litigation was forced to expend similar energies. Here, too, as noted, certain cases Plaintiff cited in support of her arguments stood for the opposite result from that which Plaintiff stated in her briefs. This kind of activity not only wastes precious and limited judicial resources, but it also drives up the cost of litigation unnecessarily for those who must defend against or seek to prosecute claims on behalf of paying clients, given the underpinnings of the American Rule that attaches to most civil litigation in this country."

Clark v. JPMorgan Chase Bank, N.A. E.D. Michigan (USA) 19 August 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Misrepresented Case Law (1)
Plaintiff's motion denied as frivolous; reply and sur-reply struck; plaintiff ordered to show cause
Source: Jesse Schaefer
Garces v. Hernandez Fifth Circuit CA (USA) 19 August 2025 Pro Se Litigant Implied
Fabricated Case Law (5)
Admonishment and Warning
Williams v. Kirch CA Indiana (USA) 18 August 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Admonishment
In re Sonja Helvig DeRosa-Grund S.D. Texas (Bankruptcy) (USA) 18 August 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
False Quotes Case Law (2)
Case dismissed with prejudice for one year

The debtor, Sonja Helvig DeRosa-Grund, engaged in substantial abuse of the Chapter 13 process by filing numerous frivolous motions and making false allegations against opposing counsel. The debtor repeatedly cited non-existent case law and fabricated quotes from existing cases, despite being warned about this behavior. The court dismissed the case with prejudice for one year, terminated the debtor's ECF filing privileges, and imposed additional protective measures to prevent future abuse. The court found that the debtor violated Bankruptcy Rule 9011(b) by making arguments based on non-existent case law and misquoting cases.

Wang v Moutidis County Court of Victoria (Australia) 18 August 2025 Pro Se Litigant Gen AI
Fabricated Case Law (2)
False Quotes Exhibits or Submissions (1)
Misrepresented Case Law (1), Exhibits or Submissions (1)
Arguments disregarded
WCAT Decision A2501051 (Hilary Thomson) BC Workers' Compensation Appeal Tribunal (Canada) 18 August 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Misrepresented Case Law (1)
Outdated Advice Repealed Law (1)
XH v Canada Employment Insurance Commission Social Security Tribunal (Canada) 18 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Source: Courtready
Ploni v. Ashdod Port Company Ltd. Beersheba Regional Labor Court (Israel) 17 August 2025 Pro Se Litigant Implied Monetary Sanction, Adverse Costs Order 8000 ILS
Clonan v. Centrastate Healthcare system D. New Jersey (USA) 15 August 2025 Pro Se Litigant Westlaw (and others unidentified)
False Quotes Case Law (3)
Warning
Maxwell v. WestJet Airlines Ltd. Civil Resolution Tribunal (Canada) 15 August 2025 Pro Se Litigant ChatGPT
Fabricated Case Law (1)
Misrepresented Exhibits or Submissions (1)
Outdated Advice Repealed Law (1)
Argument given no weight
Source: Steve Finlay
Kuzniar v General Dental Council Employment Tribunal (UK) 15 August 2025 Pro Se Litigant ChatGPT
Fabricated Case Law (1)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Tribunal declined to award costs
Yashcheshen v. Saskatchewan Government Insurance KB Saskatchewan (Canada) 15 August 2025 Pro Se Litigant Implied
False Quotes Case Law (1)
Source: Courtready
Monster Energy Company v. John H. Owoc S.D. Florida (USA) 14 August 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
Community service and certification requirement for future filings

The court imposed sanctions under Rule 11, requiring Mr. Owoc to complete 10 hours of community service and to certify the accuracy of legal citations in future filings if AI is used. No monetary penalty was imposed.

Johnny McMurry, Jr. v. Neiders Company LLC, et al. W.D. Washington (USA) 14 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Court admonished plaintiff for citing a non-existent case and warned of potential Rule 11 sanctions; no sanction imposed.
Oready, LLC (1) GAO (USA) 13 August 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
Misrepresented Case Law (1)
Warning

"Second, the protester's explanation--that it was “manual mismatches in secondary summaries” that caused the citation errors (Protester's Resp., Aug. 8, 2025, at 1)--does not meaningfully explain the number of citation errors in the protester's filings. Indeed, Oready's patently erroneous citations are far removed from mere typographical or scrivener's errors, and instead, bear the hallmarks of the use of a large-language model or other artificial intelligence (AI) without adequate verification that the generated results were accurate. "

Goya v. Hayashida CA Florida (4th D) (USA) 13 August 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Warning

" We have the authority to sanction Wife under Florida Rule of Appellate Procedure 9.410(a) for failure to comply with Florida Rule of Appellate Procedure 9.210(c). See Gutierrez v. Gutierrez, 399 So. 3d 1185, 1188 (Fla. 3d DCA 2024). However, we decline to do so. Our decision is tempered by the fact that Wife is defending a judgment on appeal in an unrepresented capacity, Husband has not sought the imposition of sanctions, and Wife has not brought any other meritless or frivolous filings in this Court. See id. at 1187–88; Al-Hamim, 564 P.3d at 1125–26. Instead, we admonish Wife for her counterfeit brief and warn her that the Court will not regard similar infractions as mildly in the future. "

Holloway v Beckles First-tier Tribunal (UK) 12 August 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
Costs Order 750 GBP
Herr v. Elos Environmental, LLC E.D. Louisiana (USA) 11 August 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
False Quotes Case Law (1)
Warning
Source: Jesse Schaefer
Lori Chavez-DeRemer v. NAB, LLC, Asia Trinh, and Nicole Brown D. Nevada (USA) 11 August 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Warning
Source: Jesse Schaefer
Blinds to Go Inc. c. Blachley Quebec SC (Canada) 11 August 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
May v Costaras NSW CA (Australia) 8 August 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
Appeal dismissed. No specific sanction for AI use, but highlighted need for judicial vigilance.