Re: Actual case aside
"You, too, are applying circular reasoning here, basing your conclusion on things you'd have to prove first to be considered facts. "
There's no circular reasoning at all. Police and court have the legal right to access the disk drive. There's a search warrant. You need a strong suspicion for a search warrant, not evidence that something will be found - if you had that evidence, you wouldn't need to search. And the accused was ordered to provide the password. As far as "contempt of court" is concerned, it doesn't matter what's on the drive. If he is totally innocent and refuses to hand over the password when ordered, it's still contempt of court.
Just like opening your front door to police with a search warrant, handing over your password is not (in this case) incriminating yourself. It's the evidence on the drive that would incriminate you, not the fact that you have the password - which is already known, otherwise there would be no contempt of court. And you have no right to hide that evidence.
A situation where you wouldn't have to reveal the password because the act would be incriminating: If you live with a roommate, and if there was an encrypted disk, likely containing child porn, but just pictures with no evidence of the owner on the disk, and if it was known beyond reasonable doubt to be either your disk or your roommates disk, then providing the password would be proof that it is yours and not your roommate's. That would be self incriminating and you wouldn't have to provide the password.