I think generally speaking, someone in possession of stolen property isn't entitled to keep that property even if they had nothing to do with the theft and had no reason to believe it was stolen. That prevents them from being guilty of a crime - but authorities can still come seize the property without compensating them at all for their loss.

In a way it's similar to getting stuck with counterfeit money. You didn't do anything wrong, but no one is going to just hand you the replacement real money you "deserve" - you just got unlucky.