Last weekend a Parisian pickpocket stole my Nexus 5X.
- Not rooted
- Locked bootloader (not modified in any way)
- Fully encrypted (and backed up)
- Locked (fingerprint/pattern)
- Updated to Oreo and current security patches
- USB Debugging turned on [MTP] (unfortunately)
Aside from the pattern lock and enabled USB debugging being weak spots, what are the chances of him successfully wiping this device and flashing a new ROM to it? In the real world, how useless will this stolen phone be to him?