Did you actually certify it was him? Also users email was changed recently so it might be a stolen or sold account.. newbies do buy high rank accounts in order to scam. Always check for that. Also, rank doesnt say anything.. its trust that does.
Anyone who account scams regardlesss of hacked or stolen is responsible for it. So if it was hacked- he shouldve secured his account correctly. Again OP sorry for your loss.