Factual error: When Ben and Sarah are on top of the train, they shout and it echoes, but there are no flat surfaces for their voices to reverberate off of.
Continuity mistake: During the scene where Ben is dancing at the gay club, his hands switch from being on his collar to down at his side then back to his collar.
Factual error: The plane crash that is pivotal in the movie would never happen in reality. Twin-engine commercial airliners are designed to be capable of flying on one engine. As the plane in the movie struck several objects before stopping, the plane did not have enough room on the runway to stop safely. In reality, the pilot would've taken off at a slower speed than normal, declared an emergency, and then returned back to the airport.