from what i understand, he was one of the miners at the beginning. if you check all his accounts, he never voted, never commented, never moved any of his steem. i am not even sure was he here when the social network started. maybe he even lost the keys... but for sure had nothing to do with anything. Except the fact that he had over 2M steem that he did not use. to me this looks like witnesses seen the opportunity to take 500.000$ from the account that will not make fus about it. 25.000$ per witness in one day, not a bad deal if you can get away with it.