Revealing mistake: When John is stuck in traffic and he walks up to the other man asking if anyone was hurt, the guy looks behind John's shoulder as if the plane is coming right behind him. Then John turns around and looks right behind him as well. But the camera then pans all the way to the side to see the plane coming in before it crashes - they were looking in the wrong place.
Revealing mistake: John is stuck in traffic and talking on his mobile phone on the highway just before the plane crashes. On the right-hand side of the screen, there's a car (Hyundai) visible through John's car side window. The car has number plates of Victoria, Australia where this particular scene was shot.
Revealing mistake: In the scene where John first discovers the patterns of numbers, he writes all of the numbers on his whiteboard. He circles the numbers he finds online with a colored marker. When he circles the number 2708 with the blue marker, he passes over the 8 with the marker, but the original black 8 and part of the 0 appears on top of the blue, showing that it was done using some overlay technique. This same effect is shown several times including when the blue and red pens mix but are still behind the black.