Judge strikes part of Anthropic's filing over a Claude citation

Music publishers are suing Anthropic over song lyrics. Anthropic filed a declaration from one of its data scientists that cited a real journal article. A lawyer at its law firm, Latham & Watkins, had asked Claude to format the citation. Claude kept the right link, volume and pages but gave a wrong title and wrong authors. A manual cite check missed it, and the publishers flagged it as a likely AI hallucination. The firm called it an honest citation mistake, not invented authority. On May 23, 2025, Magistrate Judge Susan van Keulen struck the paragraph. She wrote that the error hurt the declaration's overall credibility and weighed it in her ruling.