Yeah... I keep wondering how heavy a trail of crumbs the Mastermind has left in his or her wake. Given the information cards and other mechanics ensuring every case can be solved, there has to be something concrete we can perceive, however subtle. On the other hand, nobody is publicly acting like the mastermind, that's sort of the point of the conceit - everyone in the game has had some emotional reaction the mastermind would have to fake, whether it's Rapture and the autopsy or Lithuania now.