This is not a criminal case. The government needs to show that the coins were never released and then the burden would shift to the person possessing the item to prove it was a gift and that the person who gave the gift had the authority to do so.
I believe Mr. Lawrence is not going to be able to meet that burden because he stated he does not know how his father came into possession of it.
Once the government establishes that those pennies were ordered destroyed, the burden will shift to Mr. Lawrence to show that the penny he has in his possession was not one of those ordered destroyed. He has already admitted he can't prove that.
Well, the guy should shift the venue to criminal, because they have probably said or alleged that it was stolen.
If it was a 44 steel, or a 43 copper, neither of those were “authorized” but you don’t see them trying to get the few loose ones of those. Same deal here, how can the government prove it wasn’t a loose planchet? Hell, there’s a guy on the web with one of the actual old presses from Denver and when he overhauled it, it was filled with planchets and misstrikes.