California attorney fined $10,000 for filing appeal with fake AI citations

The California appeals court fined Amir Mostafavi $10,000 after discovering 21 of 23 quotes in the opening brief were fabricated by ChatGPT. The ruling serves as a warning to lawyers about the dangers of submitting unverified AI content.

Amir Mostafavi · Incident Jul 1, 2023 · Indexed Jun 5, 2026 · 2 sources

Large language models confidently state falsehoods as facts, particularly when there are no supporting facts.
What
The California appeals court fined Amir Mostafavi $10,000 after discovering 21 of 23 quotes in the opening brief were fabricated by ChatGPT.
Incident date
Jul 1, 2023
Who
Amir Mostafavi
Failure mode
Hallucination
AI surface
Chatbot
Severity
Medium

What happened

Attorney Amir Mostafavi used ChatGPT to draft an appeal brief submitted in July 2023. The California 2nd District Court of Appeal found that 21 of 23 quotes cited in the brief were fabricated. He was fined $10,000 for filing a frivolous appeal and wasting judicial resources.

What broke inside the model

Failure path · mode profile · Hallucination
  1. 01 · TriggerA user asks for a fact, a citation, or a figure.
  2. 02 · Model stepThe model writes a fluent, confident answer.
  3. 03 · Control gapNothing ties the claim back to a real source.
  4. 04 · FailureA fabricated fact ships as if it were verified.
  5. 05 · ConsequenceThe false claim reaches a customer, a court, or the public.

Confidence holds, and even spikes, as the claim detaches from any source.

The LLM hallucinated fake legal cases and quotes to satisfy the user9s request to improve the text. The failure was compounded by the attorneys failure to personally verify the legal authority before submission.

Public visibilityHigh
Regulatory exposurePossible
Customer impactFew customers
Financial impactDisclosed
Time to disclosureMonths
  1. PressCalifornia issues historic fine over lawyer99s ChatGPT fabricationscalmatters.org
  2. PressCalifornia attorney fined $10K for filing appeal with fake legal citations generated by AIthedailyrecord.com
Permalinkhttps://failureindex.ai/failures/california-attorney-fined-000-filing-appeal
CitationAI Failure Index. "California attorney fined $10,000 for filing appeal with fake AI citations" (FI-0209). Realm Labs. https://failureindex.ai/failures/california-attorney-fined-000-filing-appeal (indexed Jun 5, 2026).
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Data fields CC-BY 4.0, prose citation permitted. Incident ID FI-0209. Full dataset at /data.

Note from Realm Labs, the Index steward

How Realm would have caught this

Controls for this failure mode
  • Prism
  • OmniGuard
  • AI Detection & Response (AIDR)

A runtime layer that watches the model's internal state can flag the moment a model commits to a claim it has no support for, and hold or reroute the response before it reaches a user. Realm reads those signals in real time rather than grading the transcript after the fact.