AI Hallucination Cases

Court denied OSC/motion on procedural safe-harbor grounds but found defendants submitted miscited, non-existent, and inapposite authorities (and noted risk of AI-generated fake citations). Defendants accepted responsibility but no sanctions imposed.

"When criminal defense attorneys fail to comply with their ethical obligations, their conduct undermines the integrity of the judicial system. It also damages their credibility and potentially impugns the validity of the arguments they make on behalf of their clients, calling into question their competency and ability to ensure defendants are provided a meaningful opportunity to be heard. Thus, criminal defense attorneys must make every effort to confirm that the legal citations they supply exist and accurately reflect the law for which they are cited. That did not happen here."

Counsel admitted he did not verify citations. The court imposed a $1,000 sanction payable personally by counsel, ordered 1 hour CLE on generative AI, and referred him to the Disciplinary Committee.

"This case adds yet another unfortunate chapter to the story of artificial intelligence misuse in the legal profession. Here, Defendants' counsel not only included an AI-hallucinated citation and quotations in the summary judgment brief that led to the filing of this motion for sanctions, but also included multiple new AIhallucinated citations and quotations in Defendants' brief opposing this motion. In other words, counsel relied upon unvetted AI—in his telling, via inadequately supervised colleagues—to defend his use of unvetted AI."

Plaintiff's counsel filed a Notice of Errata admitting that erroneous citation and quotation errors in multiple briefs resulted from the attorney's use of generative AI. The Court refused to consider the amended briefs/errata for purposes of its decision and treated any propositions supported solely by the incorrect or made-up citations as unsupported. The Court declined to impose sanctions but warned the attorney that relying on AI without proper oversight can be sanctionable under the New Jersey Rules of Professional Conduct.

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.

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).

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 "

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.

Story available here.

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.

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.

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

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.

Order to show cause is here here.

"In total, appellant's opening brief contains 23 case quotations, 21 of which are fabrications. Appellant's reply brief contains many more fabricated quotations. And, both briefs are peppered with inaccurate citations that do not support the propositions for which they are cited.

[...]

We conclude by noting that "hallucination" is a particularly apt word to describe the darker consequences of AI. AI hallucinates facts and law to an attorney, who takes them as real and repeats them to a court. This court detected (and rejected) these particular hallucinations. But there are many instances-hopefully not in a judicial setting-where hallucinations are circulated, believed, and become "fact" and "law" in some minds. We all must guard against those instances."

The court found nearly every citation in counsel's motion to be incomplete, inaccurate, or fabricated, describing the references as typical of AI hallucinations and ordering counsel to show cause why sanctions should not be imposed.

The court granted Plaintiff's motion to strike portions of the Opening Brief after Defendant raised concerns that the brief included a non-existent quotation attributed to an existing case, a mischaracterization of an existing case, a citation to a non-existent case, and a miscitation of a case that did not address the asserted issue. The court noted counsel had been sanctioned in a separate case for citation-related deficiencies consistent with AI-generated hallucinations. The stricken portions were removed and the ALJ decision was affirmed.

"In her declaration, Attorney Cervantes described the erroneous citation as her own inadvertent error and further implied that Westlaw’s tool may have “glitched” by erroneously producing the citation. [Dkt. 31 at ¶ 4]. Specifically, she indicates that the copy citation tool mayhave inadvertently copied the wrong citation information.

Yet, that explanation seems highly improbable. The citation was incorrect in every respect and none of the sub-parts of the citation match each other, including the case docket number, reporter, pincite, court information, and date information. The likelihood of every component of a citation being simultaneously wrong due to a software malfunction in transcribing from a “correct” citation is, in the Court’s view, statistically improbable (particularly given Westlaw’s representations as to the accuracy of its tools and the apparent resources Westlaw has devoted to promoting the reputation of this tool). If one set of numbers had been transposed, or if the date were wrong, such transcription errors might be explicable. However, the fact that the party names, docket number, Westlaw citation, date, and court all failed to match, resulting in a mashup citation, cannot credibly be attributed to a software error, let alone a mistranscription or copying mistake. Rather,this Frankensteinian legal citation, stitched together from mismatched party names, docket numbers, dates, and courts, bears the hallmarks of an AI-generated hallucination, as documented in numerous published opinions and reports."

El tribunal verificó que varias sentencias invocadas por la recurrente no pudieron ser halladas en repertorios oficiales; asumió, por el beneficio de la duda, que ello provino del mal uso de herramientas de IA y advirtió la obligación profesional de verificar fuentes. Se impone recomendación al letrado y se declaran inoficiosos sus trabajos en el recurso (sin condena disciplinaria formal).

See the story here.

Counsel's Amended Motion cited a non-existent case (In re Berry Good, LLC) generated by AI. Court found the citation fabricated, counsel admitted AI use and negligence, implemented safeguards, and court declined sanctions while transmitting matter to disciplinary office. The court's reflections are worth quoting in full.

"When examined, paragraph 15 is the result of a flawed AI search that suggested an incorrect generalization falsely supported by a specific but non-existent case. Under any scenario, a suspect argument buttressed with a case from whole cloth violates the expressed and tacit norms governing the practice of law as it intersects with the courts. Simply, you cannot make stuff up to convince a court to do something.

In simpler times, that would end the inquiry with draconian consequences. The times, however, are no longer simple; thus, the inquiry does not end here.

AI interposes additional considerations that defy easy categorization or scrutiny when examining the traditional norms of practice and advocacy. Threshold, two fields of inquiry present in any AI debate. The first is whether exposition artificially generated by a computer is acceptable in what has contextually been a forum for human critical analysis, thought, and advocacy. That is not the instance here. Rather, it is the second; that is, when AI sacrifices accuracy to satisfy the consumer and that inaccuracy is advocated before the court.

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The only acceptable conclusion is that citing a made-up case is a false representation to the court that violates the expressed norms of practice, is actionable, and should bear consequences. The answer, however, to the second question —whether an artificial component alters the calculus—is more difficult.

Here, our traditional norms are challenged. In context, the traditional advocacy process begins with black letter law in the form of statutes, codes, and regulations. Then, there are judicial opinions and orders interpreting black letter law in the context of justiciable issues based on discrete facts. Lawyers cite cases for their binding or persuasive authority and have done so ever since someone started committing judicial decisions to stone, parchment, or paper. The ability to find and cite cases has evolved over time from laborious research in courthouses, to compendiums, indices, digests, reporters, advance sheets, key numbers, and now the internet.

The internet changed this dynamic in two ways. First, it streamlined, refined, and improved the research process. Users could select fields, topics, and key numbers to find and locate cases. Eventually, more specific tools, such as key words or phrases, enhanced the process. Second, and more pertinent to the present issue, AI is creating a process where instead of just finding authority, the computer also does the supplicant's thinking and analysis for them. The first innovation continues to evolve; the second is new, likewise continues to evolve, but constitutes an entirely new dimension, rather than a continuum, in legal practice. Finding has evolved into finding and thinking.

Travel back to research, the first changed dynamic. From stone to the internet, how lawyers found and used case law took many forms. Some would carefully read every case they found; some would read every page of select cases they thought pertinent; others might read the digest entry and then read only that section of the case; others might read only the digest entry; others barely read anything at all and cited anything that looked like it might support their position. Each was a personal decision by the lawyer for which he or she is accountable under the traditional norms of practice both officially—through codes of conduct and Rule 9011—and unofficially per the norms and expectations of courts.

AI compresses this historical dynamic. The research engine is now the search and thinking engine. AI finds case law and tells the subscriber that it supports their position. All the personalities described above—and known oh-so-well to us all—have become one.

Except, however, AI is flawed. In its infancy—albeit one that may be in college soon—it is immature and does not always provide accurate information or correct analysis; it may even make things up.

A tool that potentially supplants your advocacy by doing the finding and thinking for you is enticing. 3 But in the end, it is only a tool. Despite our near total and unfortunate faith in the internet, it does not relieve the attorney of his or her responsibility to make sure that the information and analysis are correct.

Reliance on AI can, however, mitigate intent. Here, Counsel is responsible for their negligence and misplaced reliance on AI, but there is no indication—and this court does not believe —that they purposely misled the court. They did not decide to make up a case. Misplaced reliance or negligence does not always equal intentional misrepresentation."

In her latter response to the Court, Counsel apologised for her use of a "a non-firm approved general AI service".

Magistrate Judge found Plaintiff's Reply contained multiple citations that do not exist, quotes not found in the cited authorities, and material mischaracterizations of cases; court concluded counsel likely used generative AI and failed to verify outputs and recommended the District Court consider Rule 11 sanctions.

In a later decision, counsel was fined 3,000 USD, plus costs, which came to 3,200 USD. Counsel was also later referred to the Bar.

As recounted here.