Deliberate mistake: There are a number of things wrong with the roller coaster scene (besides the obvious impossibility of a crash like this actually occurring):1) The restraints use ratchets to lock, not hydraulics. A coaster of this type wouldn't even have any hydraulic lines.2) No roller coaster has restraints that lower by themselves.3) The attendants didn't check all the restraints. This is ALWAYS necessary, on ANY ride.4) On any roller coaster, the Dispatch button (or "Start" in the movie) must be held down until the train is clear of the station. This is a safety feature to make sure the attendants are clear of the moving train. If the button is released before the train is clear of the station, it will stop.5) At the bottom of the lift, the lift chain curves to follow the track into the station. This is impossible, a lift chain cannot curve horizontally, only vertically (normally at the top of the hill).
Continuity mistake: In the scene where Kevin and Wendy are talking outside of the school, Kevin's hair change positions depending on the shot. At the same time, each time the shot goes back to Kevin, not only does his hair change, but the people behind him. It switches from Julie and Perry to random people, then back again.
Trivia: Notice how on the final subway they pass Booth street (a reference to John Wilkes Booth who killed Lincoln) and are supposed to get off at Oswald St (referencing Lee Harvey Oswald who assassinated Kennedy.) Another reference to Lincoln is made earlier in the film with the pictures.
Question: Here is something I really don't get. Near the end, Wendy and Kevin find out that Ian was supposed to cause Wendy's death somehow, but Ian would've already been dead. If Wendy hadn't intervened with Ian's original death, Ian wouldn't have been at the fair to cause Wendy's death. Can someone please explain this?M0vi3