AI Hallucinations Keep Costing Lawyers in Court
Key Takeaways:
- Despite internal controls, AI-generated hallucinations continue to occur in submissions from both small and large firms alike.
- Courts are increasingly strict in sanctioning AI-hallucinated case law submissions, even penalizing non-authoring associated counsel.
- Verification is non-negotiable: reliable citation-checking tools exist and firms must integrate them as core internal controls rather than optional safeguards.
Oregon
In December 2025, a federal judge in Oregon dismissed a vineyard inheritance lawsuit after finding that attorneys had relied on AI-generated research containing fabricated case law. The court dismissed the plaintiff’s claims, imposed $110,000 in sanctions and fees, and referred the matter to the Oregon State Bar. The court imposed monetary sanctions not only on the filing attorneys, but on associated local counsel. The ruling underscores growing judicial intolerance for unvetted AI use in legal filings, as well as the significant financial and ethical risks associated with hallucinated citations.
New York
On April 18, 2026, Sullivan & Cromwell filed an emergency letter asking a bankruptcy judge in the Southern District of New York to avoid sanctions after admitting that its court filing contained AI-generated hallucinations, including fabricated citations and legal errors. The firm acknowledged it failed to follow internal AI review protocols, corrected the filing, and apologized after opposing counsel flagged the issues. The letter highlights that even major firms face scrutiny and potential penalties for unverified AI use.
