Yeah I can't see why you'd get the hammer if you're telling the truth. Your guy didn't install anything wonky, even for his own games. Plus, you're sure no one else uses your laptop (i'm sure you asked him if he did), and you can't find any latent keyloggers/virus. Must be a mistake in names.
If it WAS your character, that might mean you got hacked, as stated before. Maybe CCP can check for IPs logged and see where there are inconsistencies? I mean if the last 100 logins were from an American IP address, and there were 2 right before your ban located somewhere in Romania, I'd say that's a good piece of evidence for your case :p
Anyway, good luck!