it's going to get banned, and convincing mods to unban it may become hard.
Yep, he will most likely get banned but if he was indeed hacked I don't think that it will be that hard to convince mods to unban him. Keep in mind that we are not talking about some unknown low level account but about Legendary with good reputation and history on bitcointalk so it doesn't make any sense to post something like this. And it's not like we see something like this before as there were exactly the same cases in the past and members got their accounts back.