I work at Anthropic. We were in touch with this professor the day he reported this issue. It’s very unfortunate and we’re glad everything’s been recovered. Claude clearly made a mistake here.

For anyone letting Claude work on their files, we recommend using auto mode. We recently made it the default in Claude Code, and it’s rolling out as the default in the Claude apps. I can’t say for sure if auto mode would’ve prevented this exact case, but this new default checks actions for risk before they run.