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Rodnei Chagas v. Fabricio Petinelli Vieira Coutinho

Court
TJPR - 18ª Câmara Cível
Jurisdiction
Brazil
Decided
2025-06-06
AI tool
Unidentified
Outcome
Appeal denied; appellant condemned for litigância de má-fé and ordered to pay a fine fixed at 1% of the value of the cause.
Monetary penalty
None reported

What was hallucinated

Fabricated: Case Law | Appellant submitted multiple jurisprudential citations that could not be located and were deemed non-existent; court concluded they were created by an AI search tool. || Misrepresented: Case Law | A cited REsp number was real but concerned a totally different matter, so the citation's ratio decidendi did not match the appellant's argument—court treated this as misrepresentation likely from AI.

Details

The appellant's counsel submitted an impugnação citing multiple jurisprudential precedents that the court could not locate. The court found the citations were created or altered by an AI search tool (the lawyer confessed using a 'ferramenta de busca por IA'). One cited REsp number, though numerically real, related to a different matter, supporting the conclusion of AI-produced or misrepresented authorities. The court held this conduct was manifestly temerário and amounted to litigância de má-fé, imposed a fine of 1% of the value of the cause, and denied the appeal. The court emphasized the duty of good faith and the unexcused gross error in failing to verify authorities.

Sanction teardown · TJPR - 18ª Câmara Cível, Brazil · 2025-06-06

Rodnei Chagas v. Fabricio Petinelli Vieira Coutinho

What happened

In TJPR - 18ª Câmara Cível, 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)
    Appellant submitted multiple jurisprudential citations that could not be located and were deemed non-existent; court concluded they were created by an AI search tool.
  • Misrepresented (Case Law)
    A cited REsp number was real but concerned a totally different matter, so the citation's ratio decidendi did not match the appellant's argument—court treated this as misrepresentation likely from AI.

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

Appeal denied; appellant condemned for litigância de má-fé and ordered to pay a fine fixed at 1% of the value of the cause.

Additional detail

The appellant's counsel submitted an impugnação citing multiple jurisprudential precedents that the court could not locate. The court found the citations were created or altered by an AI search tool (the lawyer confessed using a 'ferramenta de busca por IA'). One cited REsp number, though numerically real, related to a different matter, supporting the conclusion of AI-produced or misrepresented authorities. The court held this conduct was manifestly temerário and amounted to litigância de má-fé, imposed a fine of 1% of the value of the cause, and denied the appeal. The court emphasized the duty of good faith and the unexcused gross error in failing to verify authorities.

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/2883/0001082-77.2024.8.16.0075.pdf, via Damien Charlotin's public AI Hallucination Cases Database (CC0).

Source: https://www.damiencharlotin.com/documents/2883/0001082-77.2024.8.16.0075.pdf

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