Mazurek et al. v. Thomazoni
Parana State · Apr 2, 2025
- Jurisdiction
- international
- Court
- Parana State
- Record ID
- mazurek-et-al-v-thomazoni-2025-04-02
- Observed outcome
- The court denied the appeal, imposed a 1% fine of the case value for litigation in bad faith, and ordered a referral to the OAB for disciplinary review.
- Known monetary consequence
- R$1
Why this matter warrants attention
The court sanctioned the attorney for litigation in bad faith due to the submission of fabricated AI-generated case law. The court imposed a monetary fine of 1% of the case value and referred the matter to the Brazilian Bar Association (OAB) for disciplinary investigation into the attorney's professional conduct.
The court reasoned that the attorney's failure to verify the existence of cited jurisprudence, despite the availability of court records, constituted temerarious conduct and litigation in bad faith under the Brazilian Code of Civil Procedure. The court emphasized that while AI tools may assist in research, they do not replace the lawyer's professional duty of care and supervision.
ChatGPT-generated TJPR citations with retired judges are easily detected—verify relator chamber and tenure before filing.
Failure modes and consequences
- Fake Citations
- Family
- Trial
- Monetary
- Bar Referral
- Professional
- AI attribution
- Admitted
- Recorded tool
- ChatGPT
- Known monetary consequence
- R$1
- Procedural posture
- Appellate review of an interlocutory appeal (Agravo de Instrumento) in a probate/inheritance action.
Damien Charlotin case archive
Publisher document archive. The recorded document is hosted in the upstream publisher archive.
Open underlying sourceA recorded source link is not a substitute for checking the underlying order, filing, opinion, or disciplinary record.
What this record does—and does not—establish
The attorney admitted to using ChatGPT for research.
The record summarizes the outcome described in the linked public source. The recorded document is hosted in the upstream publisher archive. This page is not a substitute for the complete docket, subsequent history, or jurisdiction-specific advice.
Latest evidence review: Primary Document Verified (high confidence).
Controls suggested by the public record
- Implement mandatory verification protocols for all AI-generated legal research before inclusion in court filings.
- Cross-reference all cited case law against official court databases (e.g., Projudi) to confirm existence and relator details.
- Maintain an internal audit trail of research sources to demonstrate due diligence in the event of a challenge.
- Ensure all legal staff are trained on the ethical risks of using generative AI in professional practice.