Corrected entry: When Jim and Grace notice Sean Bean driving in the family's car, they are trying to warn the family while driving side by side next to their car. They eventually crash and have a very lengthy fall before they come out to see the family's car driving past them away. However, considering the length of the fall, wouldn't the family's car be much farther away? One can say that the family had stopped to see the crash, so why did they do nothing about it, and keep driving?
Corrected entry: When the sheriff shoots John Ryder near the end of the movie, he has a bullet proof vest on. Where'd he get this? I highly doubt the police would care if a murdering convict was shot. And he didn't put it on after he killed the cops in the car with him; there wasn't enough time in between that point and the point where the sheriff shoots him.