Marvin Elkind needs money in his dotage and is trying to flog his memoirs.
Let’s please keep that in mind. He’d probably claim Hoffa was kidnapped by a war party from Omicron Persi’i IV if he thought it would sell.
Hoffa was snuffed all right and I really don’t give a damn where they dumped him.
Hence, he picks a burial site that is completely inaccessible and therefore unverifiable.
Just aslong as he’s dead.