Nonsense. If that was true then things like backups and cloud sync couldn't happen when the device is locked. But of course they do, meaning the keys are still

Nonsense. If that was true then things like backups and cloud sync couldn't happen when the device is locked. But of course they do, meaning the keys are still sitting there freely accessed by the CPU, along with all the data on disk. Your camera example is not at all convincing of anything special going on, since that's also the camera behavior of other OS's (like Android) that don't purge the keys. That's far more easily implemented as just a basic app policy than some security system that yanks the file system out from underneath running processes.