I read elsewhere that Bill thought that if he took the dossier, that it would confirm to the others without a doubt that he was The Mole, so he didn't, in a last-ditch attempt to throw them off the sent. Too little too late, I'd say. Still, it's a heck of a lot better than a Mole who constantly earns more money than any Player throughout the entire season. That's no Mole at all. That's "The Helper" (aka "The Worst Mole Ever").