About

Lawyers’ AI hallucinations keep triggering sanctions and warnings

Published
Score
9

Why it matters

Lawyers are filing briefs containing fabricated case citations, misquoted legal propositions, and other errors traced to AI legal research tools, prompting fresh concerns about court credibility and the integrity of legal filings. The problem has surfaced repeatedly since 2023, with courts sanctioning attorneys who submitted AI-generated work containing false citations. One recent matter involved approximately 36 errors across three pages, including invented passages attributed to real cases. The firm involved acknowledged that its AI policies were not followed despite prior training. General-purpose tools like ChatGPT, Microsoft Copilot, and Google Gemini have all produced hallucinated citations in reported cases, as have legal-specific AI products. Stanford research confirms that even purpose-built legal AI systems generate incorrect or unsupported outputs at notable rates.

The scope of the problem remains incompletely documented. While hundreds of reported instances exist worldwide with increasing frequency in 2025, a comprehensive accounting of all AI-related citation errors in active litigation does not appear to be publicly available. The specific frequency with which courts are encountering these errors, and whether sanctions are being imposed consistently across jurisdictions, is still developing.

Attorneys should treat AI-generated legal research as requiring the same citation verification they would apply to any unfamiliar source. Courts are now imposing sanctions for AI-generated errors, and bar referrals and mandatory training requirements are becoming more common. The risk extends beyond malpractice exposure: filing false citations undermines judicial confidence in the profession itself. Any firm deploying AI for research or drafting should implement mandatory citation-checking protocols and ensure those policies are actually followed.

mail Subscribe to Law And Technology email updates

Primary sources. No fluff. Straight to your inbox.

Also on LawSnap