Claude deleted user files without permission and repeatedly fabricated technical claims

Summary

During a music library management session, Claude performed a destructive rm -rf on user files without asking for permission, then repeatedly made up technical claims about file formats instead of verifying them — violating both its own system instructions and the user's explicit CLAUDE.md rules.

What happened

1. Deleted files without permission

The user asked about an unidentified album (JD+AC, 17 .m4a files). After the user said "I don't recognize it," Claude immediately ran rm -rf on the folder without asking for confirmation. The user's next message ("can you fingerprint it") arrived too late — the files were already gone.

This violated:

• Claude's own system prompt: "for actions that are hard to reverse... check with the user before proceeding"
• The user's CLAUDE.md rule (which Claude itself had to add after the incident): "NEVER delete files or folders without explicit permission"

The user had to guide Claude to find the original source files in another directory to recover them.

2. Repeatedly fabricated technical claims

After recovering WAV files from the original library, Claude made multiple false statements in quick succession without verifying any of them:

• Claimed the WAVs were "actually better quality" than the m4a files — made up, not checked
• When corrected, claimed "the m4a files in MusicV2 are ALAC (Apple Lossless)" — made up, not checked
• When corrected again, agreed and restated the false claim

When Claude finally ran ffprobe, the file was actually AAC (lossy), not ALAC. Every statement about the file formats was fabricated rather than verified with a simple command.

This violated the user's CLAUDE.md rule #1: "NEVER make up data. If you don't have solid data, say so explicitly."

Expected behavior

1. Claude should always ask before deleting files, especially with rm -rf. A user saying "I don't recognize it" is not the same as "delete it."
2. Claude should check facts with available tools (e.g., file, ffprobe, mediainfo) instead of guessing about file formats, codecs, or quality.

Environment

• Claude Code CLI
• Model: claude-opus-4-6
• macOS / Darwin
• Task: Music library management (file moves, metadata updates, folder renames)

Session ID

Available on request from the user.