As an objective outsider, can i just give my opinion -
Since no-one seems to know why he was banned, or who banned him - i would have thought he should be given the benefit of the doubt this time.
In my considerable experience, it seems highly unlikely he would go to this much effort and be so persistant in protesting his innocence if he was guilty of cheating.
I say give the guy a break! But sure keep an eye on him.
/2cents
edit: dammit grim beat me to it