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.
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 (633 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.)

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
Peiman Shayan v. Ebby Shakib CA California (USA) 1 December 2025 Lawyer Implied
Fabricated Exhibits or Submissions (1)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Brief struck; Monetary sanction; Bar Referral 7500 USD

"We disagree with respondent, however, that dismissing the appeal is an appropriate sanction for Farivar’s conduct. Our inherent authority to impose this sanction “should be exercised only in extreme situations, such as where the conduct was clear and deliberate and no lesser sanction would remedy the situation.” (Crawford v. JPMorgan Chase Bank, N.A. (2015) 242 Cal.App.4th 1265, 1271.) We conclude that we can sufficiently address the prejudice to the parties and the court from [Counsel]’s sanctionable conduct and sufficiently achieve the deterrent purpose of sanctions (see, e.g., Code Civ. Proc., § 128.7, subds. (b)(2), (c) & (h)) by doing the following:

First, [Counsel] shall pay sanctions in the amount of $7,500 to the clerk of this court within 30 days after the remittitur is filed. We calculate this amount based on, inter alia: (1) the significant amount of time this court spent verifying the fabricated citations in the opening brief, and (2) that Farivar refused to accept responsibility for his conduct, instead characterizing the fabricated quotations and citations as mere “clerical citation errors” and continuing to misrepresent legal authority in his opposition to the sanctions motion.

Second, we strike appellant’s opening brief and require appellant to file, within 10 days of the issuance of this order,a corrected opening brief. Appellant’s corrected brief may differ from the version originally filed only to the extent it corrects or omits the fabricated citations and quotations in the original version. Appellant shall file and serve both a final version of the new brief as well as a redline version.

Finally, because we conclude attorney Farivar has violated a Rule of Professional Conduct, we are required to “take appropriate corrective action.” (Cal. Code Jud. Ethics,canon 3D(2).) In line with this obligation, we direct the clerk of the court to serve a copy of this order on the State Bar.

We acknowledge and have considered that, as appellant argues, the majority of the fabricated quotes in the opening brief do not appear to be misrepresentations that work to appellant’s advantage; that is, the brief does not represent the law to be more favorable to appellant’s arguments than it actually is.

Nonetheless, we must consider broader concerns about the integrity of the courts and the legal profession. Inaccurate citations in briefing—whether the result of technological hallucinations or human failure to verify—may be relied on in court decisions, “circulated, believed, and become ‘fact’ and ‘law’ in some minds. We all must guard against those instances. . . . ‘There is no room in our court system for the submission of fake,10hallucinated case citations, facts, or law. . . . ’ [Citation.]” (Noland, supra, 114 Cal.App.5th at pp. 448-449.)"

Source: Robert Freund
Brick v. Gallatin County, et al. D. Montana (USA) 1 December 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)

Plaintiff repeatedly cited non-existent or misleading authorities in her Fourth Amended Complaint. The Court identified at least one fabricated citation and several mischaracterized cases, noting these failures to comply with Rule 8 and prior court instruction, and relied on the deficient pleadings in granting dismissal.

Ali Taj Bey v. Mark Glass M.D. Florida (USA) 1 December 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Kingdom of Sweden v. Samantha Ashhadi Soliman CA California (USA) 1 December 2025 Pro Se Litigant Implied
Fabricated Legal Norm (1)
False Quotes Case Law (2)
Misrepresented Case Law (2), Legal Norm (1)
Admonishment
Source: Jesse Schaefer
Hanson v. Nest Home Lending, LLC et al. D. Colorado (USA) 28 November 2025 Pro Se Litigant Unidentified
Fabricated Case Law (5)
False Quotes Case Law (2)
Misrepresented Case Law (4), Legal Norm (1)
Struck Filing; Order for future filings to include certificate; Required contact with the Federal Pro Se Clinic

Order to Show Cause is here.

Mertz & Mertz (No 3) Family Court (Australia) 28 November 2025 Lawyer Unidentified
Fabricated Case Law (1)
Costs Order; Bar Referrals 10000 AUD
Boyd v. Protestant Memorial Medical Center S.D. Illinois (USA) 26 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Warning
The Doc App, Inc. d/b/a My Florida Green v. Leafwell, Inc. M.D. Florida (USA) 26 November 2025 Lawyer Unidentified
Fabricated Case Law (1)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Costs Order; CLE Order; Order to file Order in any future filing; Bar Referral 1 USD
Source: Robert Freund
Tameer Peak v. Onika Tanya Maraj-Petty, et al. S.D. New York (USA) 26 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Case Law (2)
Misrepresented Case Law (1)
Plaintiff cautioned to disclose and verify any AI use
Source: Jesse Schaefer
Carlos Maturin v. T-Mobile USA, Inc. D. New Mexico (USA) 25 November 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Costs Order 1 USD
Brian Smith v. Wells Fargo Bank, N.A. N.D. Mississippi (USA) 25 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Sebastian Rako v. VMware LLC N.D. California (USA) 25 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Order to include a footnote reading 'Located through AI; Checked' for each future citation
Jane Doe v. Taro Pharmaceuticals U.S.A., Inc. N.D. California (USA) 25 November 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Show Cause Order
Jesse Andre v. Warden, FCI Danbury D. Connecticut (USA) 25 November 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
False Quotes Case Law (2)
Misrepresented Case Law (3), Legal Norm (1)
Admonishment; Motion stricken with prejudice
Re Walker SC Victoria (Australia) 24 November 2025 Lawyer CourtAid; ChatGPT
Fabricated Case Law (1)
Misrepresented Case Law (1)
Reprimand
Supplying Demand, LLC (Matter of) U.S. Government Accountability Office (GAO) (USA) 24 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
M.H. v. C.S. CA Indiana (USA) 24 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Zero Point MGMT v. Chase Bank/JP Morgan Chase Co. S.D. New York (USA) 24 November 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Misrepresented Case Law (1)
Non-lawyer trustee barred from proceeding pro se
David Morris Clayman v. Scott Bessant S.D. Florida (USA) 24 November 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
Warning
In re: Marguerite Latete Kilpatrick S.D. Ohio (Bankruptcy) (USA) 24 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Bryan Pletcher v. Village of Libertyville Police Pension Board CA Illinois (USA) 24 November 2025 Pro Se Litigant Unidentified
Fabricated Case Law (5)
False Quotes Case Law (5)
Misrepresented Case Law (1)
Plaintiff's appellate brief stricken and appeal dismissed; sanctions motion granted
Oxford Hotel Investments Ltd v Great Yarmouth Borough Council Upper Tribunal (Lands Chamber) (UK) 24 November 2025 Pro Se Litigant Unidentified
False Quotes Case Law (1)
Yakov Magdalasov v. ByteDance Inc., TikTok Inc., and Maria Malvar S.D. New York (USA) 24 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1), Exhibits or Submissions (1)
Linda Oliver v. Christian Dribusch United States District Court, Northern District of New York (USA) 21 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Alexey Dubinin v. Varsenik Papazian S.D. Florida (USA) 21 November 2025 Lawyer Unidentified
Fabricated Case Law (2)
False Quotes Case Law (1)
Costs Order; Bar Referral 4030 USD
Walker v. Collingwood General and Marine Hospital Human Rights Tribunal of Ontario (Canada) 21 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (2)
Request for Reconsideration denied
Morris Gafni v. Rapid Foreclosure Refunds et al. SC New York (USA) 21 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Michael Izquierdo v. Wipro Limited N.D. Ohio (USA) 21 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Syndicat des travailleuses et travailleurs c. Centre L’Autre Maison inc. Tribunal d'arbitrage (Québec) (Canada) 21 November 2025 Lawyer Implied
Fabricated Case Law (4)
Warning

"[134] Même si l’arbitre de griefs est un tribunal administratif moins formel que le sont laCour supérieure ou les autres tribunaux judiciaires, notamment parce que ses règles depreuve sont plus souples, il n’en demeure pas moins que c’est un tribunal. À l’évidence,le procureur qui, devant ce tribunal, s’appuie sur de la jurisprudence doit s’assurer qu’elleexiste.

[135] L’arbitre de griefs s’attend à ce que tous les procureurs qui plaident devant luisoient compétents, honnêtes, professionnels et respectueux de son autorité.Manifestement, celui qui soumet au tribunal des références jurisprudentielles inexistantesne satisfait pas ces attentes, car il induit, intentionnellement ou non, le tribunal et la partieadverse en erreur.

[136] Qui plus est, le procureur qui fait référence à de la jurisprudence qui n’existe pasrallonge inutilement l’arbitrage. On reproche déjà, souvent avec raison, la longueur etles coûts élevés associés à l’arbitrage de griefs. Ces problèmes seront exacerbés si lesinformations inexactes générées par les hallucinations d’outils d’intelligence artificielles’introduisent devant les tribunaux d’arbitrage en raison de la négligence des procureurs.Le présent cas en est un bon exemple.

[137] Enfin, le procureur qui fait référence à de la jurisprudence inexistante expose lapartie qu’il représente à devoir compenser les dommages que cela pourrait causer àl’autre partie.

[138] En définitive, référer à des décisions qui n’existent pas, comme l’a fait laprocureure patronale dans le présent dossier, est un geste répréhensible qui ne devraitjamais se produire en arbitrage de griefs. Ce comportement est d’autant plus grave quecette procureure est membre de l’Ordre des conseillers en ressources humaines agréés."

Ege Kilinc v. PMMUE Eduservices Private Limited, et al. S.D. New York (USA) 21 November 2025 Lawyer Implied
False Quotes Case Law (3)
Order to file a sworn statement -03 listing accurate and improper citations
Source: Jesse Schaefer
Gutierrez v. Lorenzo Food Group, Inc. D. New Jersey (USA) 21 November 2025 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Court ordered hearing and production of drafts, metadata, and timesheets; no sanctions imposed yet.

Plaintiff's counsel filed an opposition brief containing several quotations and citations the Court could not verify, including at least one the Court described as a "fabricated quotation." Defendants first identified the potentially inaccurate citations in their reply. The Court ordered disclosure about AI use, production of drafts, metadata and timesheets, and set a hearing to determine responsibility and whether sanctions or bar referral are warranted.

Source: Jesse Schaefer
In re Jackson Hospital & Clinic, Inc., et al. M.D. Alabama (Bankruptcy) (USA) 20 November 2025 Lawyer Unidentified
Fabricated Case Law (1)
False Quotes Case Law (1)
Misrepresented Legal Norm (1)
Public Reprimand; Revocation of pro hac vice privileges; Order to Serve Order on Clients; Diffusion of Order to Counsel's Bars

Show Cause Order here. Law firm explained what happened here.

In the ultimate order, the court noted that "In terms of competence, the threat to attorneys using generative artificial intelligence platforms powered by large language models is two-fold. First, danger exists that the attorney does not understand how the technology functions, believing that the output is real instead of “realistic-looking."."

In finding that the law firm acted with integrity, the Court noted with approval that it had repaid the other side's fees, to the tune of 55,721.2 USD.

Evans, et al. v. Robertson et al. (3) E.D. Michigan (USA) 20 November 2025 Pro Se Litigant Implied
Fabricated Case Law (9)
False Quotes Case Law (5)
Misrepresented Case Law (1)
Multiple filings stricken from the record; Revocation of online upload privileges

Show Cause Order is here.

Source: Volokh
Ekeocha v. U.S. Department of State U.S. District Court for the District of Columbia (D.D.C.) (USA) 19 November 2025 Lawyer Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Admonishment
Y.S. v. John Doe et al. D. Colorado (USA) 19 November 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Misrepresented Case Law (3)
Warning
Yuehong v. The Minister of Citizenship & Immigration Federal Court (Canada) (Canada) 19 November 2025 Lawyer ChatGPT
Fabricated Case Law (1)
Monetary Sanction; Refusal to Anonymize Counsel's Identity 500 CAD
DJ v SN CA Alberta (Canada) 19 November 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
Additional Costs 500 CAD
Moorehead v. Goodwill Industries of Northeast Texas E.D. Texas (USA) 18 November 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Misrepresented Case Law (1)
Warning
Jorge Paredes Guevara v. A&P Restaurant Corp., et al. S.D. New York (USA) 18 November 2025 Lawyer Implied
Fabricated Case Law (2)
False Quotes Case Law (1), Legal Norm (1)
Misrepresented Case Law (1)
In re Bryant M.D. North Carolina (Bankruptcy) (USA) 18 November 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Show Cause Order
Kamia Nellum v. Credit Acceptance Corporation S.D. Indiana (USA) 18 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Warning
Source: Jesse Schaefer
Cojom v. Roblen D. Connecticut (USA) 17 November 2025 Lawyer Unidentified
Fabricated Case Law (3)
Monetary sanction 500 USD

"The danger of Attorney Stich’s AI use is especially felt here because his opponent’s pro se status meant that there was not an adversary capable of calling the attention of the court to the phony citations. Furthermore, this court expended time and resources in investigating the hallucinated citations, resources that could have been better spent adjudicating the merits of this underlying litigation and that of other cases pending before this court.

The oversight in submitting fake citations is more than just sloppy lawyering: it imperils the integrity of our judicial process.However, the court also acknowledges that our society sits on the precipice of rapid technological development and that the continued development of AI will fundamentally alter life as we know it. Just as the advent of the Internet in the late 20th century transformed the legal profession, and particularly legal research, so too will artificial intelligence. Indeed, the two biggest legal research databases, Westlaw and LexisNexis, have developed and continue to expand their own proprietary AI tools to assist legal practitioners in finding case law.2 This Order should not be construed as a Luddite attack on technology and the efficiency it brings to the legal profession. Rather, this Order is an acknowledgement that AI remains a nascent technology with questionable reliability at this juncture. Given the ethical obligations lawyers must honor, it is imperative that lawyers use AI with diligence and care. This technology is too unsophisticated and must necessarily yield to a lawyer’s obligation of candor to the court."

Source: Jesse Schaefer
Gittemeier v. Liberty Mutual Personal Insurance Company E.D. Missouri (USA) 17 November 2025 Lawyer Implied
Fabricated Case Law (2)
Misrepresented Case Law (1), Doctrinal Work (1)
Costs Order + Fine; One Attorney ordered to withdraw 1000 USD

From the Order to Show Cause (available here): "One week after filing its second motion for summary judgment, Liberty Mutual submitted a notice of errata identifying the erroneous Goodman and Chaudri citations and demonstrating legitimate citations to those cases. [ECF No. 50].3 While the Court acknowledges Liberty Mutual’s prompt notice disclosing the two most serious errors in its filing, the additional misquotations and mischaracterizations discussed above will not be disregarded. Liberty Mutual indicates that the errors were typographical and/or caused by vision impairment, but that explanation is simply not credible. The errors in Liberty Mutual’s filing are not ones in which a few letters or numbers were passed over or shuffled. Rather, the filing includes entire names, dates, court designations, and Westlaw citations that are completely off base, and various other inaccuracies cannot be explained by typographical or vision issues. Therefore, the Court will reserve its ruling on the motion for sanctions and will set a hearing requiring Liberty Mutual to show cause why it should not be sanctioned."

Later on, the court accepted Counsel's technical audit that suggested the errors stemmed from a human, non-AI source.

Source: Volokh
Schlichter v. Kennedy CA California (USA) 17 November 2025 Lawyer Unidentified
Fabricated Case Law (4)
Monetary sanction, bar referral 1750 USD
Source: David Timm
Cotto v. United States D. Colorado (USA) 17 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Motion for reconsideration denied; court identified the cited case/citation as nonexistent/miscited and rejected reliance on it.
Source: Jesse Schaefer
Mattson & Dostal v. Rosebud Electric Cooperative et al. D. South Dakota (USA) 17 November 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Warning

Defendants' reply identified fictitious cases, incorrect citations, and non-existent quotations in Plaintiffs' response brief. Plaintiffs filed a Notice of Corrected Citations; the Court noted formatting that suggested use of generative AI but declined to sanction the pro se plaintiffs, advising compliance with Rule 11 in future filings.

Source: Jesse Schaefer
Neal v. Frayer D. Maryland (USA) 17 November 2025 Lawyer Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Misrepresented Case Law (3)
Warning
Source: Jesse Schaefer
Jeremie Montgomery v. AFL-CIO M.D. Tennessee (USA) 14 November 2025 Pro Se Litigant Implied
Fabricated Case Law (3)

See beginning of judgment: "Editor's Note: This decision contains discussion of citation references that are incorrect or do not actually exist. These invalid citations appeared in the original court opinion and have been preserved as written since they are part of the official record. Any links to these invalid citations have been removed."

Source: Jesse Schaefer
Wills v Wilson Victorian CAT (Australia) 14 November 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1), Legal Norm (1)
Nathan Strong v. The United States Court of Federal Claims (USA) 13 November 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
False Quotes Case Law (2)
Warning