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 (1150 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)
Ronald H. Foster v. Author Success Publishing, et al. M.D. Alabama (USA) 29 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Show Cause Order
Source: Jesse Schaefer
Sky Gardens Queensland BCCMC (Australia) 29 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1), Exhibits or Submissions (1)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Adverse costs order for "misconceived and without substance" application 2000 AUD
Bourse de l'Immobilier Multilogements inc. c. Lanthier CS Québec (Canada) 29 October 2025 Pro Se Litigant ChatGPT
Fabricated Case Law (3)
Monetary sanction 750 CAD
Ryan Andrew Nelson v. State Farm Fire and Casualty Company S.D. Georgia (USA) 28 October 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
In re: Loletha Hale, Esq. (Boston v. Williams) N.D. Georgia (Atlanta Division) (USA) 28 October 2025 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Case Law (2)
Order to notify clients; Order to file this opinion in all new cases for five years

Party later filed for reconsideration, arguing that the judge had been biased; this failed (see here).

Sehra Waheed v. SM 1 MMS, LLC, et al. S.D. New York (USA) 28 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Stelian Gheorghe v (1) BSA Ahmad Bin Hezeem & Associates LLP (2) Jimmy Haoula DIFC Court of First Instance (UAE) 28 October 2025 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Case Law (2)
Adverse costs order
The Vancor Group Inc. v. 2744364 Ontario Limited et al Ontario SCJ (Canada) 28 October 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1), other (1)
Misrepresented Case Law (1)
Admonishment
Green Building Initiative, Inc. v. Stephen R. Peacock & Green Globe Limited D. Oregon (USA) 27 October 2025 Lawyer Copilot
Fabricated Case Law (2)
Show Cause Order

Lawyer later explained that he had "used Microsoft’s Copilot for its editing functions in an effort to review and improve the draft document by fixing grammar, spelling, and improving badly phrased sentences" - not for legal research.

On November 12, 2025, the court resolved the Show Cause proceedings without formal sanctions.

Source: Volokh
U.S. Bank National Association v. Richmond D. Maine (USA) 27 October 2025 Pro Se Litigant Implied
Misrepresented Exhibits or Submissions (1)
Show Cause Order

Motion for reconsideration was later dismissed, partly because of AI misuse behaviour (see here).

In re: Sherry Ann McGann D. Colorado (Bankruptcy) (USA) 27 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Jayroe v. Progressive Casualty Insurance Company N.D. Texas (USA) 27 October 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Warning
Crowder v. Yussman CA Kentucky (USA) 24 October 2025 Lawyer Implied
Fabricated Case Law (3)
Warning

" Moreover, we take this opportunity to caution practitioners of this Commonwealth on the submission of briefs or citations without confirming their accuracy and the correctness of the resulting analysis. The abject failure to conduct due diligence when making arguments to the Court greatly impacts the profession and undermines confidence in the skills and knowledge necessary to practice as an attorney. Failure to verify substantive legal citations prior to submission to this Court is not only in derogation of the RAP, but also violates the attorney's ethical responsibilities. See Supreme Court Rule 3.130(1.1).

Mistakes occur. Oversights happen. Those types of inadvertent errors we could absolve. However, purposelessly submitting a brief to a Court of law without confirming that the cited case law even exists is an affront to the dignity of the Court system, the legal profession as a whole, the judiciary, the client, and the public at large."

In re: Sanctions Order of Kenney CA Louisiana (USA) 23 October 2025 Lawyer ChatGPT, Microsoft Copilot, Google
Fabricated Case Law (3)
False Quotes Case Law (1)
Misrepresented Case Law (1)
Costs order, 3 hours CLE on ethical use of generative AI, referral to Office of Disciplinary Counsel 1368 USD
Victoria Place Flats RTM Company Ltd & ors v Assethold Limited First-tier Tribunal (UK) 23 October 2025 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)

The judge tested Microsoft M365 Copilot and found it produced fabricated Court of Appeal citations for Qdime and an incorrect citation for Gala Unity. The Tribunal concluded Mr Gurvits used AI-generated research without adequate verification; the AI outputs were rejected as unreliable. The Tribunal criticised the conduct but did not impose professional disciplinary sanctions; remedial orders in the case related to service charge and fee reimbursement.

Appeals of Huffman Construction, LLC Armed Services Board of Contract Appeals (USA) 23 October 2025 Lawyer Unidentified
Fabricated Case Law (2), Exhibits or Submissions (2)
Misrepresented Case Law (4), Exhibits or Submissions (2)
Reply brief struck in its entirety

The Board found over 70% of citations in Huffman's reply brief inaccurate, including fabricated cases, misattributed reporter citations, cases that did not support cited propositions, and incorrect or non-existent transcript/Rule 4 citations. Counsel admitted using AI to generate portions of the brief. The Board treated the motion as one for Rule 11-type sanctions and struck the reply brief; it emphasized attorneys' duty to verify AI-generated content.

Source: David Timm
McCaster v. United States Court of Federal Claims (USA) 23 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Admonishment
Source: David Timm
Corey v. Kenneh SC North Dakota (USA) 22 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Affirmed sanctions from lower court
Re Sriram (aka Roy) High Court (UK) 22 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
University Mall v. Okorie et al. S.D. Mississippi (USA) 22 October 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
False Quotes Case Law (1)
Civil contempt 1
Mattox v. Product Innovation Research E.D. Oklahoma (USA) 22 October 2025 Lawyer ChatGPT
Fabricated Case Law (7)
False Quotes Case Law (2)
Misrepresented Case Law (3)
Pleadings struck; public reprimands; monetary sanctions; remedial filing and certification requirements 28495 USD

The Court found 28 false or misleading citations across 11 pleadings (14 fabricated, 14 erroneous/misquoted). Mr. Howie admitted use of ChatGPT and failure to verify citations. The Court applied Rule 11(b) and its AI framework (verification, candor/correction, accountability) and imposed sanctions and restitution. Fines of 3,000, 2,000, and 1,000 USD on individual attorneys, plus opposing party's costs and fees,

N-BAR Trade v. Amazon D.C. DC (USA) 22 October 2025 Lawyer Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Warning
Alexandria Jones v. DC Office of Unified Communications D.C. DC (USA) 22 October 2025 Lawyer Implied
False Quotes Case Law (1)
Warning
John Weaver v. Shasta Services W.D. Pennsylvania (USA) 22 October 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Guardian Piazza D'Oro LLC v. Ward Ozaeta CA California (USA) 22 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Richard M. Zelma v. Wonder Group Inc. D. New Jersey (USA) 22 October 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1)
False Quotes Case Law (2)
Sanctions deferred
In re Bittrex D. Delaware (USA) 22 October 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Misrepresented Case Law (1)
Pete v. Facebook Meta Platforms E.D. Texas (USA) 22 October 2025 Pro Se Litigant Implied
False Quotes Case Law (2)
FCA US LLC v. Stan Steele/Steele Services National Arbitration Forum (UDRP) (USA) 22 October 2025 Pro Se Litigant Implied
False Quotes Case Law (2)
Warning
Wu v. Murray CA British Columbia (Canada) 21 October 2025 Pro Se Litigant Unidentified
Fabricated Case Law (2)
Costs order took hallucinations into account
Thomas Joseph Goddard v. Sares-Regis Group, Inc., et al. N.D. California (USA) 21 October 2025 Pro Se Litigant Implied
Fabricated Exhibits or Submissions (2)
Misrepresented Exhibits or Submissions (1)
Leila Kasso v. Police Officers’ Federation of Minneapolis D. Minnesota (USA) 21 October 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
False Quotes Case Law (1)
Misrepresented Case Law (2)
Warning

The City argued—and the Court found—that the pro se plaintiff repeatedly cited nonexistent or inaccurately attributed caselaw likely generated by AI. The Court found these citations violated Rule 11, warned the plaintiff, and declined to award fees or impose sanctions. The court preserved the original incorrect citations in the opinion as part of the record.

Arch Insurance Company v. A3 Development, LLC S.D. Florida (USA) 21 October 2025 Lawyer Implied
Fabricated Case Law (2)
Order to Show Cause
Rimu Capital Ltd. v. Ader et al. S.D. New York (USA) 21 October 2025 Lawyer Unidentified
Fabricated Case Law (1)
Warning
Megan Cowden v. US Treasury & IRS E.D. Missouri (USA) 20 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
False Quotes Case Law (1)

The court was unable to locate one of the plaintiff's case citations and several quotations attributed to other cases; the court suspected portions of the filings were AI-generated and noted potential Rule 11 violations but did not impose sanctions.

Tippecanoe County Assessor v. Craig Goergen Indiana Tax Court (USA) 17 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Artur Sargsyan v. Amazon.com Inc. W.D. Washington (USA) 17 October 2025 Pro Se Litigant Implied
Fabricated Case Law (1)
Warning
Mitchell Taylor Button et al. v. John Jimison (1) W.D. Washington (USA) 17 October 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
False Quotes Case Law (4)
Order include signed certification
Safe Choice, LLC v. City of Cleveland N.D. Ohio (USA) 17 October 2025 Lawyer Amicus (Casemine)
Fabricated Case Law (4)
Misrepresented Case Law (6)
Monetary Sanction; Referral to the Bar; Order to serve decision on clinet; 7500 USD

Order to show cause is here.

Twyla Leach Minnesota DHS et al. D. Minnesota (USA) 17 October 2025 Pro Se Litigant Implied
False Quotes Case Law (1)
Warning
Chi Keung Lee & others v Blackpool B&B Limited First-tier Tribunal (UK) 17 October 2025 Pro Se Litigant Unidentified
Fabricated Case Law (1), Legal Norm (1)
Monetary Sanction 227 GBP
Serafin v. United States Department of State, et al. E.D. Missouri (USA) 16 October 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Misrepresented Case Law (2)
Warning
Conrad Smith et al. v. Donald J. Trump et al. D.C. D.C. (USA) 16 October 2025 Lawyer Implied
Fabricated Legal Norm (1)
False Quotes Legal Norm (1)
Show Cause Order
X.L. v. Z.L. et al Ontario SCJ (Canada) 16 October 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Misrepresented Case Law (6)
No reliance on authorities submitted; Monetary Sanction 1000 CAD

Costs were awarded here.

Polinski v. USA Court of Federal Claims (USA) 15 October 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
Warning

"On September 3, 2025, Plaintiff filed his response to the court’s order to file copies of the cases he cited (#7). Therein, Plaintiff avers he took “concrete remedial steps” to cure the time wasted by his use of artificial-intelligence-hallucinated case citations, including “submission of the verified opinions as exhibits” (#7 at 2). Indeed, Plaintiff’s response stresses how he“obtained authentic copies” of those cases and “attached” them as exhibits. See (id.).

Plaintiff did not attach any exhibits to his response to this court’s order. The court is convinced that those two case citations are AI-hallucinated. Plaintiff’s insistence that they exist—and that he provided copies of them to this court—is bewildering."

Nima Ghadimi v. Arizona Bank & Trust, et al. D. Arizona (USA) 15 October 2025 Pro Se Litigant Implied
Fabricated Case Law (2)
Warning
Charles C. Force v. Capital One, N.A., et al. M.D. Florida (USA) 15 October 2025 Pro Se Litigant Implied
Fabricated Case Law (3)
False Quotes Case Law (1)
Misrepresented Case Law (2)
Outdated Advice Overturned Case Law (1)
Filings stricken; Show Cause Order
Provincia del Chubut v. PRA Chubut (Argentina) 15 October 2025 Judge Implied
Misrepresented other (1)
Judgment annuled, new trial before different judge ordered

(Not an hallucination per se, but worth adding to the database anyway.)

Lugasi (Aklim Systems) v. Netivot Municipality Beersheba Magistrate's Court (Israel) 15 October 2025 Pro Se Litigant ChatGPT
Fabricated Exhibits or Submissions (1)
No reliance on hallucinated material
YK v. The High State Prosecutor's Office in Prague) Supreme Administrative Court (Czech Republic) 15 October 2025 Lawyer Implied
Fabricated Case Law (1)
False Quotes Case Law (1)