Revealing mistake: When the baby is pulled out of Layla, you can tell that it's not a newborn baby because he is missing his umbilical cord.
Revealing mistake: After Charlie gets his thumb shot off by Dickey near the end, in most of the shots you can easily see that Charlie is bending his thumb behind the rest of his hand instead of computer graphics removing it.
Revealing mistake: Charlie tells Irene to jump from the moving train when he can't catch up to it. When Irene jumps, the train is standing still. It only appears to be moving because of clever camera manipulation.
Revealing mistake: Near the end of the movie when Irene falls off the bridge and Charlie follows, and when the boy's helicopter comes to save them, it is cloudy then a split second later sunny, then back again throughout the entire scene.
Revealing mistake: When Hank crashes the car through the shop, look at the barber's chair. You can see it's a stunt double for the actor.