You bring up an important PSA type point:

People should ALWAYS verify that they can restore from backups.

Can't tell you how many clients I've had to tell that although they were backing up regularly, "their backup solution of choice was hosing the data the whole time.. Oh and it uses a prorpietary storage format so I can't even go after the files manually."

Had they ever tried a restore they would have been made aware of the situation before it was too late. Trust but verify.