Mike's an idiot...! SPOILER
I know he's meant to put his honour above everything else, but surely common sense would dictate that you don't GIVE AWAY the present your new best friend (and very rich employer) has just given you!
Still, quite liked the film - some of the fights are awesome and Chiwetel Ejiofor is awesome. But it's also typically Mamet, meaning that just about every major character but the one he cares about is monumentally flawed.