15 Jul 2026United StatesUnidentified AI drafting tool
In a published opinion of July 2026, the Arizona Court of Appeals found that a self-represented appellant's opening brief in a probate dispute contained eight citations, six of them deficient, including two cases that do not exist. In a written explanation and at a hearing on the false citations he acknowledged relying on generative AI to write the brief and said he did nothing to verify the citations. The court struck the inaccurate and false citations, rejected the appeal because no supportive authority remained, held that citing a hallucinated case is sanctionable whether or not it is intended, and ordered him to pay the share of the other party's attorney's fees traceable to the fake citations. Because he said he did not intend to deceive and is not legally trained, the court chose this narrow sanction over contempt or fines. It described the opinion as the first published Arizona ruling on generative AI hallucinations in filings.
Core + contextual relations Low reported severity Regulatory Action
AI involvement supported · Causal attribution established · 1 source · Added 18/10/2026
31 Mar 2026 to 11 Sept 2026United StatesIrys (reported)
A Los Angeles County Superior Court judge ordered a senior associate at Musick, Peeler & Garrett, the outside firm defending State Farm in a homeowner's lawsuit over a fire-damaged home, to pay a $999.99 sanction after the associate's motions in limine cited cases, quotations and holdings that did not exist, Law360 reported on 14 September 2026. In a declaration reproduced by Reason's Volokh Conspiracy, the associate said she used an AI program called Irys to prepare the motions, did not check some of the citations, and wrongly believed the program was cite-checked through the firm's Westlaw subscription; she confirmed seven non-existent case citations across eight motions. The plaintiff's lawyers found the citations and raised them at a status conference on 7 August 2026. The firm acknowledged citations that appeared to be AI hallucinations, and its lead trial counsel apologised to the court and the plaintiff. According to Law360, the judge had considered up to $5,000, and the amount set is one cent below the level at which California law requires a court to notify the State Bar.
Core concern Low reported severity Regulatory Action
AI involvement supported · Causal attribution supported · 4 sources · Added 17/10/2026
2026SpainUnidentified AI drafting tool
The Criminal Chamber of the High Court of Justice of the Canary Islands (TSJC) fined a lawyer 420 euros for breaching the duty of truthfulness and good faith, after an appeal the lawyer filed contained 48 citations of Supreme Court judgments and a report of the General Council of the Judiciary that did not exist. According to the court's order, as described in its press release of 13 February 2026, the lawyer used a general-purpose AI tool to draft the appeal and did not check a single citation against the free public case-law database; the court's documentalist verified that the references were false. The court referred the matter to the lawyer's bar association for possible disciplinary action and set the fine at about half the annual cost of a legal-specific AI tool, taking into account that the lawyer admitted the facts and expressed remorse. The court had first flagged the citations in its judgment dismissing the appeal, reported on 5 January 2026, which opened a separate proceeding. The lawyer told the court of comments and mockery from colleagues after the case became public.
Core concern Low reported severity Regulatory Action
AI involvement supported · Causal attribution established · 3 sources, 2 underlying accounts · Added 16/10/2026
5 Feb 2026 to 9 Oct 2026United StatesvLex, Paxton AI and NotebookLM (reported)
In a federal trademark suit in the U.S. District Court for the Southern District of New York, the court on 5 February 2026 struck a company defendant's motion papers and entered default judgment against it as a sanction on its lawyer, after his filings repeatedly cited nonexistent cases and misattributed quotations. The lawyer said he had found and cite-checked cases with AI tools (vLex and Paxton AI) and used NotebookLM to review a later submission; the court rejected his explanations and found he acted in bad faith. On 9 October 2026 the court described the citations as produced by generative AI and ordered the lawyer to pay $38,877.59 in fees and costs to the firm of a co-defendant's former lawyer, who had reported the false citations to the court.
Core + contextual relations Medium reported severity
AI involvement supported · Causal attribution established · 2 sources, 1 underlying account · Added 16/10/2026
24 Apr 2026United StatesUnidentified AI research tool
On 24 April 2026 the Supreme Court of Alabama dismissed an appeal by two siblings in a family dispute over living trusts because their lawyer, W. Perry Hall, had filed briefs in which most of the legal authorities were misquoted or did not exist. The court said they appeared to be AI hallucinations, and at a show-cause hearing in February 2026 Hall admitted that many authorities did not exist and that he had improperly used AI to obtain them. The court ordered Hall to pay the opposing party's fees and costs of $17,200 and double appeal costs, barred him from filing in the court without a co-signing attorney and referred him to the Alabama State Bar. It said the dismissal was imposed as a sanction because of the particularly egregious facts. One justice, concurring in part and dissenting in part, objected to dismissing the appeal as a sanction for the lawyer's conduct but would have affirmed the judgment against the clients on the merits.
Core + contextual relations Medium reported severity Regulatory Action
AI involvement supported · Causal attribution established · 1 source · Added 14/10/2026