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 (3 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.

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State
Party
Nature – Category
Nature – Subcategory

Case Court / Jurisdiction Date ▼ Party Using AI AI Tool ⓘ Nature of Hallucination Outcome / Sanction Monetary Penalty Details
In Re CorMedix D.C. New Jersey (USA) 23 July 2025 Judge ChatGPT
Fabricated Case Law (1)
False Quotes Case Law (4), Exhibits or Submissions (1)
Misrepresented Case Law (2)
Opinion withdrawn by judge —

In a letter, the defendant pointed out the errors in the Opinion - prompting the judge to withdraw it through a minute order, without offering a rationale.

The judge later issued a new opinion, without mentioning or addressing what had happened.

In a context of a congressional investigation, the Judge later explained what happened, and blamed the intern.
Mississippi AoE et al v. Board of Trustees of SIHL et al. Mississippi (USA) 20 July 2025 Judge Perplexity
False Quotes Legal Norm (1)
Misrepresented Exhibits or Submissions (5)
Judge withdrew the order —

Story here, including a link to the original order full of hallucinations.

Judge did not explain why he withdrew the original order and replaced it with a new one, prompting counsel to move for a preservation of the record and an explanation (motion).

The judge dismissed the motion on 1 August 2025, stating: "The original version of that Order contained clerical errors referencing improper parties and factual allegations. The Court promptly corrected those errors and issued an Amended and Corrected TRO on the docket. [...] The Court corrected the record, notified the parties, and the corrected TRO is the controlling order. No further explanation is warranted."

In the context of a subsequent congressional investigation, the judge explained what happened, and blamed his law clerk.
Shahid v. Esaam Georgia CA (USA) 30 June 2025 Judge, Lawyer Unidentified
Fabricated Case Law (14)
Misrepresented Case Law (4), Legal Norm (1)
Case remanded; monetary penalty 2500 USD

" After the trial court entered a final judgment and decree of divorce, Nimat Shahid (“Wife”) filed a petition to reopen the case and set aside the final judgment, arguing that service by publication was improper. The trial court denied the motion, using an order that relied upon non-existent case law."

"We are troubled by the citation of bogus cases in the trial court's order. As the reviewing court, we make no findings of fact as to how this impropriety occurred, observing only that the order purports to have been prepared by Husband's attorney, Diana Lynch. We further note that Lynch had cited the two fictitious cases that made it into the trial court's order in Husband's response to the petition to reopen, and she cited additional fake cases both in that Response and in the Appellee's Brief filed in this Court. "