He didn't do it because it can't be done past day six; this has been covered. He also begged and pleaded for white_eyes to research exorcisms in time for one more of them to be done -- white_eyes doesn't contest this. Finally, if Methos were the demon, why draw negative attention to himself by choosing to run an "exorcism" on someone seemingly no one but him suspected? He'd had suggestions from several people he could have drawn from to cover his butt.

Your reasons for voting him are fake, YLC. I'd be voting you right now if I were still alive.