What was hallucinated

Fabricated: Case Law | Initial petition cited non-existent judicial precedents to support the claim; the defense flagged the fabrications and the court recognized them as such and as bad-faith conduct. || Fabricated: Case Law | Filing used names of TRT-3 desembargadores to simulate jurisprudence that does not exist, attempting to influence the court; the judge noted such 'jurisprudence' was easily verifiable as nonexistent. || Fabricated: Case Law | Citation of randomly created 'súmulas'; the court stated they were nonexistent, unnecessary, and easily checked on the TRT-3 website.

Details

Counsel for the claimant admitted to using an AI tool to draft the initial legal document without verifying its content. This resulted in the creation of non-existent judicial precedents to support the claimant's case. The court found this to be a serious violation of procedural loyalty and good faith, as it attempted to deceive the court and the opposing party. Consequently, the claimant was fined 5% of the updated value of the case for litigating in bad faith, although the lawyer's apologies were partially accepted, preventing a higher fine.

Sanction teardown · Regional Labour Court, Brazil · 2025-07-02

ATSum 0010525-47.2025.5.03.0037

What happened

In Regional Labour Court, Brazil, a filing relied on an unnamed/unconfirmed AI tool to help draft legal argument. The court identified the following problems with the citations in that filing:

Fabricated (Case Law)

Initial petition cited non-existent judicial precedents to support the claim; the defense flagged the fabrications and the court recognized them as such and as bad-faith conduct.
Fabricated (Case Law)

Filing used names of TRT-3 desembargadores to simulate jurisprudence that does not exist, attempting to influence the court; the judge noted such 'jurisprudence' was easily verifiable as nonexistent.
Fabricated (Case Law)

Citation of randomly created 'súmulas'; the court stated they were nonexistent, unnecessary, and easily checked on the TRT-3 website.

Which AI tool

an unnamed/unconfirmed AI tool. Note: Charlotin's public database records tool attribution only where a court order, brief, or reporting on the matter states it explicitly; "unidentified" or "implied" means the record indicates AI use but does not name a specific product — we do not guess.

Outcome

Monetary Sanctions (monetary penalty: 1 .)

Additional detail

How Citation Safe would have caught this

Citation Safe runs three deterministic layers before a brief is filed: (1) does the citation exist against CourtListener's database of published opinions, (2) if quoted, does that exact language appear in the source, (3) does the cited case actually support the proposition it is cited for. Fabricated case citations fail Layer 1. Fabricated or misattributed quotations fail Layer 2 even when the underlying case is real. Misrepresented holdings — a real case cited for a proposition it does not support — are the target of Layer 3. None of these checks involve asking another language model whether the citation looks right; they are lookups and text-matches against the actual source, which is why a hallucinated citation has to survive a direct lookup against the authoritative source — not another model's opinion — to earn a VERIFIED stamp; our measured false-verify rate is published live at /quality.

Check a brief before you file it → · See our live false-verify rate

Source: https://www.damiencharlotin.com/documents/564/28a8e98659526f2c66a0b6e2715ccc13.pdf, via Damien Charlotin's public AI Hallucination Cases Database (CC0).

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