From the discussion about the anonymously posted Prime Controller keys it seems that when transferring a PC from one person to another there is nothing keeping the original owner from using the same key afterwards. Is this correct? Also, is it possible for the first owner to access the coins in the new address after a transfer? I am specifically wondering if this is the proof that the whole mutiny story and theft of Paycoins/Prime Controllers from Homero is bullshit.
As far as I understand, keeping a copy of a key is possible, it's actually nearly impossible to ensure that a copy is not kept. But no, it does not give access to coins. The coins would have be transferred via a regular blockchain transaction.