[His first instinct is outright denial- and though Anakin doesn't lurch away, his rejection of this as fact is clear all over his face. He knows the Chancellor, that's impossible. Anakin would know, and if he was a Sith lord he would never let-]

Obi-Wan- [He pleads, shoulders sagging] That doesn't make any sense. Played both sides of the war? How? He's been a friend of the Council for years, Count Dooku captured him more than once!