The way courts generally work, they need a proof you've done something wrong to condemn you. If there are a dozen friends who had the wiping rights to your keys, and they knew you'd been arrested, any of them could have decided to wipe the key, just in case.

Unless the judge can prove who did it, he can't condemn the 13 (12+you) of you because one of you did something wrong. Besides, the 12 innocents don't know who did it either, so they can't snitch.

It requires the wiping procedure to be impractically hard to trace back, but that can be done.