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 (1228 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.

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)
Mitchell Taylor Button & Dusty Button v. Juliet Doherty et al. S.D. New York (USA) 30 September 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Case Law (2)
Misrepresented Exhibits or Submissions (1)
Certification requirement for future AI-assisted filings.
Tajudin bin Gulam Rasul and another v Suriaya bte Haja Mohideen High Court (Singapore) 29 September 2025 Lawyer Unidentified
Fabricated Case Law (1)
Costs and order to inform client 800 SGD

CC cited a fictitious AI-generated case in written submissions. The Defendant's counsel located the error, CC admitted the authority was AI-generated and did not exist, and the Court found CC acted improperly, ordering personal costs of $800.

Munoz v. Lopez CA California (USA) 29 September 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Chapter Kris Jackson v. BOK Financial Corporation, et al. (2) N.D. Oklahoma (USA) 29 September 2025 Pro Se Litigant Implied
Fabricated Case Law (5)
False Quotes Case Law (1)
Show Cause Order
ANPV & SAPV v Secretary of State for the Home Department Upper Tribunal (UK) 29 September 2025 Lawyer Microsoft Copilot
Fabricated Case Law (2)
Misrepresented Case Law (4)
Show Cause Order
Sonkin v. Roll Profile Ltd Haifa Labour Court (Israel) 29 September 2025 Lawyer Implied
Fabricated Case Law (1)
Monetary Fine 2000 ILS
Ilan Harush v. Roee Alfasi Magistrate's Court, Rehovot (Israel) 28 September 2025 Lawyer Unidentified
Fabricated Case Law (1)
Disallowed Costs Order
Jade Riley Burch v. HCA Healthcare D. Nevada (USA) 26 September 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
Misrepresented Case Law (1)
Warning
Reddy v Saroya CA Alberta (Canada) 26 September 2025 Lawyer Implied
Fabricated Case Law (1)
Adverse Costs Order 17550 CAD

The appellant's original factum contained references to seven cases that could not be located (six allegedly decisions of this Court). Respondent flagged the issue; appellant's counsel ultimately acknowledged a contractor-drafted factum and that a large language model may have been used. The Court allowed an amended factum and reserved costs, warning that use of LLM without verification may attract costs, contempt proceedings, or Law Society referral.

Monetary sanction was determined in a subsequent decision (available here).

Pennantia v. Rose Cay Maritime S.D. New York (USA) 26 September 2025 Lawyer Implied
False Quotes Case Law (2)
No sanctions

In a later order, the court declined to order any sanctions in "light of counsel's acknowledgment of the fact that the quotations at issue were not independently verified against the actual opinions and acceptance of responsibility and the remedial measures subsequently put in place to avoid a repetition of the errors "

Loftong v. Grove Farms Cir. Ct., DeSoto Minnesota (USA) 26 September 2025 Lawyer FastCase
Fabricated Case Law (1)
Adverse Costs Order; 6 hours CLE; Bar Referral 7472 USD
Oready, LLC (2) GAO (USA) 25 September 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
Misrepresented Case Law (1)
Protests dismissed for abuse

Actually the fourth order in that case that pertains to hallucinations; a first, June 5 Order is only mentioned in a second, June 18 order that does not call out what appears to be hallucinated references.

Source: David Timm
Evans, et al. v. Robertson et al. (2) E.D. Michigan (USA) 25 September 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
False Quotes Case Law (3)
Warning to both parties
Source: Volokh
Greenopolis Welfare Association (GWA) v. Narender Singh et al. Dehli High Court (India) 25 September 2025 Lawyer Unidentified
Fabricated Case Law (1)
False Quotes Case Law (1)
Petition withdrawn
Eric Andrew Perez v. Dr. Neil C. Evans, et al. S.D. New York (USA) 25 September 2025 Pro Se Litigant ChatGPT
Fabricated Case Law (1)
Misrepresented Case Law (1)
Warning
Source: Jesse Schaefer
Alexander Shaporov v. PIPPD P.O. Matthew Levine, et al. D. New Jersey (USA) 25 September 2025 Lawyer Implied
Fabricated Case Law (3)
False Quotes Case Law (1)
Misrepresented Case Law (2)
Show Cause Order

The district court independently found numerous inaccurate quotations and citations in Plaintiff's Opposition—misquoted language attributed to binding Third Circuit authority, Westlaw citations and dates that were incorrect or non-existent, and miscited pincites. The court concluded the pattern suggested the brief may have been prepared using generative AI without adequate verification and ordered counsel to show cause under Rule 11 and ethical rules. The court preserved the inaccuracies in the official opinion but removed links to invalid citations.

Beschluss 2-13 S 56/24 LG Frankfurt a. M. (Germany) 25 September 2025 Lawyer Unidentified
False Quotes Case Law (1)

Story available here.

BFG aka Byline Financial v. Pierce RE Holdings & Brewster N.D. Illinois (USA) 24 September 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Kenisha Black v. Mississippi DRS & Howard S.D. Mississippi (USA) 24 September 2025 Lawyer Unidentified
Fabricated Case Law (1)
Court accepted corrected briefs

Plaintiff's counsel admitted that the opening memorandum and reply brief contained false AI-generated content. Counsel filed corrected memoranda; the court noted a Rule 11 violation but accepted the corrections and declined to impose sanctions or require additional briefing.

Source: Jesse Schaefer
Melinda L'Shay Johnson v. MINI of Las Vegas D. Nevada (USA) 24 September 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
T.M. v. M.M. CA Indiana (USA) 24 September 2025 Pro Se Litigant Implied
Fabricated Case Law (5)
False Quotes Case Law (1)
Misrepresented Exhibits or Submissions (1), Legal Norm (1)
Warning

The Court preserved the invalid citations in the opinion as they are part of the record, admonished that fabricated or incorrect citations frustrate review and may lead to reprimand or sanction.

Salem v. Deputy Head Federal PSLREB (Canada) 24 September 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
Misrepresented Case Law (1)
Puerto Rico Soccer League NFP, Corp., et al. v. Federación Puertorriqueña de Futbol, et al. D.C. Puerto Rico (USA) 23 September 2025 Lawyer Unidentified
Fabricated Case Law (6)
False Quotes Case Law (25)
Misrepresented Case Law (24)
Order to pay opposing counsel's fees 24492 USD

In the Order, the court stated: "A simple Google search would have shown the problems in some of Plaintiffs’ citations. In other instances, a quick search of the opinion Plaintiffs cited to would have revealed problems. Levying appropriate sanctions here promotes deterrence without being overly punitive, as contemplated by Rule 11(c)(4).

The Court notes that, rather than showing contrition, the Memorandum in Compliance strikes a defiant and deflective tone. (Docket No. 190). It also contains more of the errors that plagued Plaintiffs’ previous four filings. For example, in the “Legal Standard” section of the memorandum, Plaintiffs cite to two cases for the proposition that sanctions are an “extreme remedy” appropriate for instances of prejudice or bad faith. One case makes no mention of sanctions and neither contain the proffered quote Id. at 3. The Court finds it problematic that Plaintiffs responded to a show cause order to address the problem of multiple inaccurate citations by providing a response containing more erroneous citations."

Monetary sanction was decided in a subsequent decision dated 23 September 2025, available here.

Stile Carpentry Ltd. v. 2004424 Ontario CA Ontario (Canada) 23 September 2025 Pro Se Litigant Implied
Fabricated Case Law (1), Exhibits or Submissions (1), Legal Norm (1)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Sentenza del 23.09.2025 Tribunale di Latina (Italy) 23 September 2025 Lawyer Unidentified
Fabricated Case Law (1)
Misrepresented Case Law (1)
Monetary Sanction 2000 EUR
Source: LeggeZero
Lipe v. Albuquerque Public Schools (1) D. New Mexico (USA) 22 September 2025 Lawyer Implied
Fabricated Case Law (3)
False Quotes Case Law (2)
Misrepresented Case Law (6)
Monetary sanction; self-report to state bars 3000 USD

Original Show Cause Order is here. Court noted that Counsel was still citing fabricated authorities, even though show cause proceedings are ongoing in parallel.

Vision Management Group v. Constant Aviation N.D. Ohio (USA) 22 September 2025 Lawyer Implied
Fabricated Case Law (2)
Warning, arguments disregarded
In re Molina E.D. New York (Bankruptcy) (USA) 22 September 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
Order to sworn accuracy of citations
Gibralter v. DMS Flowers E.D. California (USA) 19 September 2025 Lawyer Unidentified
Fabricated Case Law (1)
Order to show cause discharged; Admonishment
Martin v. Redstone Federal Credit Union N.D Alabama (USA) 19 September 2025 Pro Se Litigant Implied
Fabricated Case Law (8)
Warning
Ali v. IT People Corporation E.D. Michigan (USA) 19 September 2025 Pro Se Litigant Implied
Fabricated Legal Norm (1)
False Quotes Case Law (1)
Misrepresented Legal Norm (1)
Monetary Sanction 600 USD
United States v. Malik D. Maryland (USA) 19 September 2025 Pro Se Litigant Implied
Fabricated Legal Norm (1)
False Quotes Doctrinal Work (1)
Warning
Source: Jesse Schaefer
Cingel v. Ferreri CA Indiana (USA) 19 September 2025 Pro Se Litigant Implied
Fabricated Case Law (2), Legal Norm (3)
Misrepresented Case Law (1), Legal Norm (2)
Warning
Pelishek v. City of Sheboygan E.D. Wisconsin (USA) 18 September 2025 Lawyer Westlaw's Quick Check and AI Case Search Tool
Fabricated Case Law (1)
False Quotes Case Law (3)
Misrepresented Case Law (9), Exhibits or Submissions (4)
Monetary Sanction 4500 USD

Case involved counsel sanctioned in Coomer v. Lindell. In the OSC Order, the court noted:

"The fact that Kachouroff and DeMaster corrected some of their misrepresentations before the court or the defendants identified them would ordinarily mitigate their conduct. But the reality is that Kachouroff and DeMaster acted only after the Colorado District Court in Coomer v. Lindell noted similar misconduct. That so many misrepresentations persist supports the inference that counsel’s conduct was not mere negligence but an intentional effort to mislead the court."

In her response to the OSC (available here), Counsel disclosed the Westlaw tools she had used.

OTG New York, Inc. v. Ottogi America, Inc. D. New Jersey (USA) 18 September 2025 Lawyer Unidentified
Fabricated Case Law (1)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Monetary sanction; Plaintiff's Reply withdrawn and stricken; order to self-report to bar(s) and serve client with order 3000 USD
Source: Robert Freund
Eric V. Mitchel II v. Stellantis Financial Services E.D. Virginia (USA) 18 September 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Warning

"The Court respectfully proposes that the time may be near for an exception to the Erickson liberal-construction rule, where a pro se individual relies on AI to draft pleadings and thus blurs the line between what is a good faith pro se assertion of an actionable claim and what is a computer-generated morass that only serves to waste court time and resources."

Source: Jesse Schaefer
Hugo v Affinity Education Group Pty Ltd Family Court (Australia) 18 September 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Family law Case Gent (Belgium) 18 September 2025 Lawyer Implied
Fabricated Case Law (2), Doctrinal Work (1)
False Quotes Case Law (1), Legal Norm (2)
Misrepresented Legal Norm (2)
Disregarded all fictitious/unfindable sources, admonished counsel
Peugeot Citroen Argentina et al. v. Sumarismo CA General Roca (Argentina) 18 September 2025 Lawyer Implied
Fabricated Case Law (3)
Counsel's Work not Counted for Fees; Referral to the Bar
Tsupko v. Kinetic Advantage, LLC S.D. Indiana (USA) 17 September 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Misrepresented other (1)
Admonishment and Warning
Source: Robert Freund
Jeramiah Brown v. Fat Dough Incorp., doing business as Dominos Pizza N.D. New York (USA) 17 September 2025 Pro Se Litigant ChatGPT
Fabricated Case Law (1)
Warning
Latasha Hill v. Auto Club Family Insurance Company S.D. Mississippi (USA) 17 September 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Misrepresented Case Law (2)
Warning
Source: Jesse Schaefer
Santree v. Eveangel Hines CA North Carolina (USA) 17 September 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Appeal dismissed for lack of genuine argument

Defendant's reply brief contained citations that did not support her arguments and included at least one non-existent case citation; the court concluded these errors suggest use of AI and treated the issues as abandonment under Rule 28(b)(6), dismissing the appeal.

Source: Jesse Schaefer
Howe v. NSW Department of Education NSW Industrial Relations Commission (Australia) 17 September 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Misrepresented Case Law (2)
BKA Holdings v. Sam CA Illinois (USA) 16 September 2025 Pro Se Litigant Implied
Fabricated Case Law (4)
Plaintiff awarded attorney fees and costs for spotting hallucinated authority 1 USD
Fagan v. Barnhiser, Nanologix, et al. D. New Jersey (USA) 16 September 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Warning
R.G.L. n. 1018/2025 Tribunale di Torino (Italy) 16 September 2025 Lawyer Unidentified Misrepresented / incoherent and largely irrelevant jurisprudential and normative citations produced with AI support Monetary sanction 1500 EUR
Ezenwa Ebem v. Bondi et al. N.D. Texas (USA) 15 September 2025 Pro Se Litigant Implied
Fabricated Exhibits or Submissions (1)
Misrepresented Exhibits or Submissions (1)
Warning

The court found the plaintiff's filings contained misrepresentations of the record—specifically, a purported 'Clerk's Entry of Default' that never existed and a claim that an Immigration Judge made a final binding APA finding. The court attributed these misrepresentations to likely AI generation, warned the plaintiff about consequences for false statements, and construed the misrepresentations as AI misapplication rather than deliberate deception.

Nga Huynh v. Joseph Desimone CA California (USA) 15 September 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Warning

The appellant (self-represented) cited two nonexistent cases in her appellate brief. The respondent flagged the fictitious citations and requested sanctions. The court found the citations fictitious, discussed sanction authority and AI-generated filings, but declined to impose sanctions because the request was procedurally inappropriate, the appellant corrected filings promptly, and the legal propositions were, in fact, supported by existing authority.

Gabriel v. Mareco CA Buenos Aires (Argentina) 15 September 2025 Lawyer Implied
Fabricated Case Law (3)
Recurso de apelación declarado desierto; costas al apelante; se notificará al letrado y al Colegio de Abogados. No se impusieron sanciones profesionales.