Continuity mistake: The teenage girl in the first house they sleep over in hands Bruce Willis a mug of tea the following morning. First it shows her front and his back, and she turns the mug so the handle faces him as he takes it. Then it cuts to facing him from behind her, and the mug handle is now facing away from him.
Continuity mistake: When Harvey finally gets his opportunity to pick up the hitchhiker, she approaches his car and stands at the driver's side. At one point, the camera is on Harvey, and to the left, you can see her reflection in the car's shiny paint job and she is smiling. When the camera cuts to her, she isn't.
Factual error: In the beginning of the movie, there is a scene where Joe Blake (Bruce Willis) confronts his teenage hostage, who has just found a shotgun in the home. Willis overwhelms the boy and takes the gun from him. When Willis empties the gun by sliding the pump action, the live shotgun shell falls to the bedroom floor. However, when the shell lands it sounds very much like an empty brass pistol case bouncing concrete. It happens again, later in the movie. Willis' character empties the same shotgun after shooting it into the ceiling during a bank robbery. The empty shotgun shell makes the identical sound when it hits the bank floor.