May v Costaras
NSW CA · Aug 8, 2025
What happened in this matter?
The NSW Court of Appeal dismissed the appeal in a property trust dispute. While no specific sanction was imposed for the respondent's use of generative AI, the Court formally noted the respondent's reliance on a hallucinated case citation and irrelevant legal authorities, emphasizing the need for judicial vigilance regarding AI-generated submissions.
- Why the court cared
- The Court reasoned that the respondent's use of generative AI resulted in submissions that were largely unintelligible and included a non-existent case citation, which added unnecessary cost and complexity to the proceedings. The Court concluded that while AI may improve access to justice, it requires judicial vigilance and strict verification of all legal references to ensure the integrity of the administration of justice.
- Why it matters now
- NSW Court of Appeal flagged the need for judicial vigilance — assume any pro-se authority list contains at least one hallucination.
Why this matter is tracked
In an appeal before the New South Wales Court of Appeal, the self-represented respondent utilized generative AI to prepare oral submissions and a list of authorities. The Court found that the respondent's submissions were largely unintelligible and irrelevant, and that the list of authorities included a non-existent case, 'Tate v Ragg [2004] NSWCA 306'. The Court dismissed the appeal on substantive grounds but used the incident to highlight the risks of AI-generated hallucinations in legal proceedings. The Chief Justice emphasized the necessity for judicial vigilance and the professional duty of practitioners to verify all legal references, noting that unrepresented litigants may lack the capacity to discern the accuracy of AI-generated content.
NSW Court of Appeal flagged the need for judicial vigilance — assume any pro-se authority list contains at least one hallucination.
Record details
What the record establishes about AI use
The respondent admitted to using an artificial intelligence program to prepare her submissions.
Appeal from the Supreme Court of New South Wales (Equity Division) to the New South Wales Court of Appeal.
Correction behavior is not separately verified in the current record.
Tracked discrepancy record
1 citation, quotation, or authority issues are recorded in the source dataset.
- Fabricated: Case Law | Respondent’s list of authorities included a non-existent case; the Court confirmed no such case exists.
Questions this record answers
- What happened in May v Costaras?
- The NSW Court of Appeal dismissed the appeal in a property trust dispute. While no specific sanction was imposed for the respondent's use of generative AI, the Court formally noted the respondent's reliance on a hallucinated case citation and irrelevant legal authorities, emphasizing the need for judicial vigilance regarding AI-generated submissions.
- Why does May v Costaras matter for legal AI risk?
- NSW Court of Appeal flagged the need for judicial vigilance — assume any pro-se authority list contains at least one hallucination.
- What does the public record establish about May v Costaras?
- 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.
- Which source supports this May v Costaras summary?
- The recorded source is Damien Charlotin case archive. It is classified as publisher document archive; review the linked material and subsequent docket history before relying on this summary.
Related matters
Related by court, jurisdiction, tool, or classified failure pattern. Similarity does not imply the same facts or outcome.