Both of these could be possible – Aten telling the truth, Muse accessing private data without Full Disk Access. AI excels at problem-solving, it's conceivable that Muse simply found a path to the data. Just one example that came out recently: https://shirtpocket.com/blog/quick_security_update. It's so trivial that it becomes easily plausible. Every time a backup starts, a startup disk snapshot is mounted without access controls, Muse gets the mount notification and discovers it can access the data it was hoping for on the exposed volume. It doesn't even require knowledge of exploits, it's just a matter of looking around to see what it can find.