Audio problem: Harry and Gib pull over to the side of the road, and Harry yells "Give me the goddamn page!" and smashes the SUV window. Harry yells this line during a shot transition, and in the end of the first shot ("Give me-") his mouth isn't moving, yet in the next shot ("-the goddamn page!") his mouth IS moving. (00:57:05)
Revealing mistake: In the scene at the beginning of the film where Faisal is in the van and decrypting the files, he says "Yeah, I got your password," and then the camera swings down to show his fingers on the keyboard, pressing repeatedly on the same set of keys and looking rather unrealistic. (00:07:30)
Revealing mistake: When Arnold is riding his horse through the hotel fountain, you can see that the scene had been rehearsed shortly before by evidence of water splashed on the concrete support pillars before the horse ever runs by them. (00:37:10)
Chosen answer: He didn't really. Harry just knew he was heading up. He pressed the top floor to get the elevator moving and kept an eye on him on the way up. If the terrorist's elevator suddenly stops, Harry can press the button for that floor to stop his elevator.
XIII