I'll change the negative feedback to neutral but something still doesn't seem 100% right about this. The fact that he deals in bitcoin for years yet can't provide a signed message from an address associated with the account is a bit suspicious.
Not I cannot I have explained many times before, those wallets I used are
ALL from exchanges. I don't have any private keys to them. Also, change my assistant's negative to neutral, please. Nothing happened to us. No one scammed, nothing.
My Assistant's Account:
https://bitcointalk.org/index.php?action=trust;u=1895733