Revealing mistake: There is a safe house in The Following DLC map with two kids playing some hand held video games sitting in a room. If you look at them closely, the screens are not on with the devices not even actually powered on with black screens. Despite this the kids rapidly press buttons like they are playing them, and you can hear the sounds of games being played.
Revealing mistake: When you get the random encounter of Richie, he will start speaking. When he's closed to finished, suddenly his mouth will stop moving with his words for most of what he says, but then start again at a few sentences, only to stop again.