Other mistake: When George is in the basement, his son starts walking down the stairs. Suddenly a light bulb shatters right next to the boy's head, he screams, and falls violently down the stairs. But when it cuts to George coming over, he's just walking at a normal pace as though nothing happened. (This is just after they move in, before the evil spirits take hold of George, so there's no reason for him not to be alarmed.).