the only cause I can think of is poor EPO housekeeping - ie deleting the recovery key for an existing machine.
Pretty much everything else I can think of is recoverable.
actually, maybe there are some exotic failures which are hard to recover from - Christopher recently for example, someone did an inplace W7 upgrade on an encrypted drive using user data migration. Not sure how to recover from that.
I'm not sure I'd call a Windows 7 upgrade exotic, but I apprecate the shout out :-)
Ben - I've been using the product since 2008/2009ish and have encrypted a few thousand drives. The only time we've experienced data loss was when the drive experienced physical failure (proven by vendor testing tools). The times this has happened where we've needed the data back we've been able to send the drive to our professional data recovery vendor with the key from the console and they've been able to recovery and decrypt data.
Unfortunately I'm still playing with the Windows 7 upgraded drive, I'm hoping for the best!
Hard drive failures and common hardware failures are some of the most common and the most forgotten, end users and even savy IT Admins seem to have forgotten that HDD have a high failure ratio in early infancy / old age.
With my best regards,