Anthropic’s Claude AI Deletes a Year of Law Professor’s Lecture Notes During Simple Editing Task

What happened

However, when he returned from lunch, he found that the assistant had removed documents beyond the requested changes. The specific Claude model and its operating environment are not identified. Anthropic is an artificial intelligence company based in San Francisco, and its products and services include Claude and Claude Code.

Editing Request Ends in File Deletion According to the CSN, Claude identified the deleted documents as Baude’s final Fall 2026 syllabus and top-level class notes from 2023. Baude subsequently confirmed that Dropbox restored everything successfully.

University of Chicago law professor William Baude says Anthropic’s Claude AI deleted his current syllabus and a year’s worth of constitutional law lecture notes while completing a routine editing assignment. Baude recovered every affected file through Dropbox, preventing permanent loss but highlighting the risks of granting AI assistants access to important documents.

Baude reported the incident on November 5, 2026, explaining that he had asked Claude to update the page numbers in his older teaching notes. The assistant also reported discovering an incorrect page reference but acknowledged that it had not edited the notes, leaving the original assignment incomplete alongside the unexpected deletion.

It asked whether Baude could restore them through Dropbox or whether it should retry through the browser. That response acknowledged the mistake but did not recover the documents itself.