The fastest way to turn an AI time-saver into a career risk is to file what it wrote without checking it. Generative AI can hallucinate — produce confident, well-formatted case citations, quotations and holdings that simply do not exist. In legal filings this has already cost attorneys money, credibility and, in some cases, their standing in a matter. Here is what the record shows and how to stay out of it.
How often AI invents law
The problem is not rare. A 2024 study, "Large Legal Fictions" (Dahl, Magesh, Suzgun and Ho — a Stanford–Yale effort published in the Journal of Legal Analysis), found that general-purpose large language models hallucinated on 58% to 88% of verifiable questions about federal case law. General chatbots were never built to be legal-citation engines, and it shows.
The fallout is now measurable. Damien Charlotin's AI Hallucination Cases database catalogued 486 cases worldwide — 324 of them in U.S. courts — by October 2025. By one vendor's tally (SurePoint, reporting Charlotin's data), U.S. courts recorded 487 AI-error instances in 2025, more than ten times the prior year, with licensed attorneys — not just self-represented litigants — accounting for a large share. (These are point-in-time counts that keep growing.)
The cases every lawyer should know
Mata v. Avianca (S.D.N.Y., June 2023). The seminal warning. Judge P. Kevin Castel fined two attorneys and their firm $5,000 after they filed a brief citing fake ChatGPT-generated case law. His opinion set the tone that has held ever since: using AI is not itself improper, but "existing rules impose a gatekeeping role on attorneys to ensure the accuracy of their filings."
Coomer v. Lindell (D. Colo., July 2025). Judge Nina Wang sanctioned two attorneys $3,000 each for a brief with nearly thirty defective AI-generated citations — misquotes, misstated holdings, non-existent cases. The court grounded it in Federal Rule of Civil Procedure 11: it is the signing attorney's obligation to ensure the accuracy of the submission.
Noland v. Land of the Free (Cal. Ct. App., 2d Dist., Sept. 2025). California's first published opinion on AI-fabricated citations. Attorney Amir Mostafavi was sanctioned $10,000 after the court found 21 of 23 case quotations in his opening brief were fabricated by AI tools including ChatGPT. A notable wrinkle: the court declined to award fees to opposing counsel — because they failed to catch the fakes either.
Sanctions have gone beyond fines, too — courts have ordered state-bar referrals, dismissed filings and even disqualified counsel in AI-citation cases.
The one rule underneath all of them
Across every decision the principle is identical: the attorney bears a personal, non-delegable duty to read and verify every citation, regardless of which tool produced the draft. As one court put it, no brief or pleading should contain a citation the responsible attorney has not personally read and confirmed. AI does not shift that duty; it just makes it easier to violate.
How to avoid becoming a headline
The fix is process, not fear. Draft with AI if it helps, but verify before you file — check that every case exists, that quotations are accurate, and that holdings actually say what the draft claims. We lay out a concrete process in how to review an AI-drafted document, and the ethics backdrop in can lawyers use AI to draft legal documents.
It also helps to use tools built for legal drafting rather than a raw consumer chatbot. eObig's AI assistant is designed to help produce and edit documents you then review and sign — not to invent authority. The lawyer still verifies; the tool just makes the first draft faster.
In brief
- Generative AI hallucinates fake citations at high rates (58–88% in one 2024 Stanford–Yale study of federal case-law questions).
- AI-fabricated filings surged in 2025 — hundreds of U.S. court instances, many by licensed attorneys.
- Courts have sanctioned lawyers from $3,000 to $10,000 and beyond (Mata, Coomer, Noland), plus bar referrals and disqualification.
- The governing rule is constant: you must personally read and verify every citation — the tool never carries that duty.
General information, not legal advice. See AI-assisted drafting built for review-and-sign in eObig's AI features.