Revealing mistake: When Jack breaks into the Albert Dock Road building where the hijackers have their hideout, he enters through a wire-mesh-reinforced roof window. From below you see that he hits it once, causing a huge shower of big glass pieces (as if there were no wire mesh), and then the whole, almost intact pane comes down as if the mesh hadn't been connected to the frame. (00:29:55)
Revealing mistake: When one of the hijackers shoots at the truck that pulls the gangway with the police marksmen, the windshield cracks all over at the first shot but there is no hole. However, a big splash of blood hits the glass from the inside. The second shot makes a big hole in the windshield on the passenger's side, but the broken glass falls on the hood, against the momentum of the bullet. (00:14:55)
Revealing mistake: Jack executes Maldic, who is sitting in a Taxi, by shooting at him about a dozen times. While there is blood all over the taxi Maldic doesn't suffer any visible injury. (00:51:25)