I think it's possible that Saul could be the mole if you want to call him that. Other than Brody, he was the only other person to have direct contact with that prisoner before he sliced himself and what was up with the whole lie-detector thing last season with Saul? That just seemed awkward.
I think all of that was just to plant suspection on him, to make him the scapegoat for this season where more than half of it we think it is Saul where at the end there is some swerve/turn. I think it's going to be someone we haven't met yet or the black boss guy.