London’s High Court rebuked Pinsent Masons after junior counsel presented false statutory citations generated by AI during an insolvency filing. Judge Mark Mullen warned that work pressure does not excuse a lapse in verifying court submissions. The error surfaced when the judge challenged the reference, exposing a gap in the firm’s AI oversight.

The junior lawyer, dubbed “LA” in the ruling, worked under a senior associate and partner who claimed ignorance of the AI use. The transcript revealed the tool warned it was “not fully confident” in the statutory wording, urging manual verification. Mullen noted that outsourcing research to AI undermines judicial trust and that legal professionals must retain ultimate responsibility.

Pinsent Masons has apologized, self‑referenced the incident to the Solicitors Regulation Authority, and pledged stronger safeguards amid rising scrutiny of AI in legal work. The firm, whose equity partners earned an average £797,000 last year, faces reputational risk that could affect client confidence and future litigation fees. The court will monitor compliance without initiating contempt proceedings.

Industry observers note this case joins previous High Court rulings that flagged false citations and AI hallucinations in filings. Sullivan & Cromwell recently faced a similar indictment after a bankruptcy submission contained multiple fabricated references. These incidents underscore a growing regulatory push to enforce stricter AI vetting protocols across law firms.