Revealing mistake: At the end of the film Vanessa gets crazy because Bob kills her grandma, and she starts beating him up in the caravan, hitting him and throwing various stuff at him. Throughout the scene, Reese Witherspoon's' stunt double is really obvious. Her hair looks completely different!!!
Revealing mistake: In the fight scene at the end, Vanessa is hitting Bob, and Bob has a gun. However he repeatedly fires it over and over without reloading. (01:31:40)
Revealing mistake: When Bob and Vanessa are battling at the end of the film, he fires 22 shots before he dies. Besides the obvious fact that the gun doesn't hold that many bullets and wasn't reloaded, there was no sparks or smoke from the gun on almost all of the shots and although he seemed to be firing randomly around the room, there are no holes in the walls or even in window like there should have been, especially seeing as a couple of shots made it outside to the policemen.
Revealing mistake: In the shot of Vanessa's dead Grandma, her closed eyes flutter and her tongue moves. (01:31:20)
Answer: Police will often attempt to anger people they are interrogating, so they accidentally make a confession.
LorgSkyegon