He impersonated by using his status as if he was the devs and he is not The devs didn't put that, he did
His status said: this player under investigation Pimd which is not impersonation cause technically many here are trying to figure out who his main is if he has one. That calls for investigating and collecting evidence. So if he's clever he can fight it if he wants. There's no where in TOU that says one can't use PIMD at the end of a statement. Getting him silenced wont do anything. He hasn't done anything to be banned either.
Plus one must prove that he pretended to be devs. I doubt they can. If I was him that'd be my defense. Your status is your status so you can put whatever you feel on it as long as it doesn't violate the TOU and his did not.
That last part is a good point, I still call it an impersonation of sorts but maybe such a thing is just not against the ToU I'm just making an assumption and he's probably silenced for all the complaints against him or something like that