Comment Re:After reading over other posts... (Score 1) 560
The mistake of saying that it contains evidence and that he has the capacity to unlock it is a huge mistake. In general (IANAL), in order to compel you to do something like unlock a safe, the prosecution needs to have a reasonable belief that the safe contains evidence relevant to the case, that you know how to unlock the safe, and that the safe (and/or evidence?) are yours.
He admitted all three of these. If he hadn't, then at the very least they'd have to work much harder to prove to a judge that all three were true before trying to compel him to decrypt the drive. The latter two are probably easy -- if the drive is in his physical possession and attached to his computer, then it's reasonable to assume (though not always true) that it is both his and that he has the means to access it. But they'd need something more than a hope or a guess that it actually contained evidence to compel decryption.