Factual error: Towards the last scene, Howell and Hauer share the same shotgun (Ryder to take pop shots at Jim in the jeep, Jim to ultimately fire three shots to kill Ryder). The shotgun used can hold at most seven or eight shells, not the 12 or more that are fired between Ryder and Jim starting from when Ryder escaped the bus.
Factual error: All the police officers are described on the cast as 'troopers', but those who arrest Jim at the diner and those who pull him off the bus are actually deputy sheriffs, not state troopers. They are not wearing uniform, are not driving cars with state police badges, are wearing stars instead of police shields, the place where he is taken after being arrested has 'Sheriff Station No.7' written on the outside wall, and the name of the sheriff's department can be seen when he is being photographed.
Answer: The windshield glass would have not broken this easily (like regular window pane glass in your home or such). I am going to guess that kind of glass hasn't been used on car windshields since at least the early 70's, if not before. The Sheriff's truck didn't appear to be that old, either.