Personally, I think this should be coming from him.... he should make his own account and appeal his own ban, seeing as he was the one who did it.
He got banned for excessive spam but he only did it because he got dared to by someone on another server and he was having problems that his account kept getting hacked
So he got dared to [thus it was intentional] but then you say his account was getting hacked? Regardless of whether the latter was true (which I'm 95% sure isn't), he's still responsible for his own account, thus he's completely responsible for what happens on it, whether he does it or someone else does.