Why 'Tamper-Evident' AI Audit Logs Are Not the Same as Proof

A new open-source tool for logging AI agent activity uses hash chains to create tamper-evident audit records, where each entry references the previous one to detect edits. However, a hash chain alone only proves a file is internally consistent — anyone holding the file can rewrite records and recompute all subsequent hashes, making the chain appear valid. A deeper problem is that when the recorder runs inside the same process as the agent, the agent itself controls what gets logged, meaning malicious or prompt-injected behavior can simply bypass the logger. External checkpointing and proxy-boundary recording, as seen in tools like Pipelock, offer stronger guarantees but still rely on the operator's honesty. The broader industry needs clearer vocabulary to distinguish between logs that are hard to alter and logs that can genuinely serve as independent evidence.