However, that's a unique case, because the authorities know the hashes of the cleartext files on his machine match the hashes of illicit media. "Foregone conclusion" so long as you believe in the mathematics behind hash collisions.

How can they possibly know that?

If that is the case then there should be no problem convicting him.

They had access to the drive at one point.

In a filesharing seneario it is common for feds to see what you got before the raid that grabs the physical drive.

Either what they have is enough for a conviction or it's not. If it is, then there's no need to actually get access to it, if it's not then it might as well not exist.

In the file sharing scenario, how would the feds know that the encrypted drive actually has the files? They can only know what they suspect is on the drive.

It isnt about absolutes. They can be reasonably certain that the drive was in use on a network.

I don’t understand this. Are the hash values stored somewhere unencrypted?

Reminds of that guy in The Crucible that gets crushed with rocks for refusing to take part in the witch trial.

I do believe you mean Giles Corey.

https://en.wikipedia.org/wiki/Giles_Corey