Revealing mistake: In one shot when the boat is pulling away from the waterfall, you can clearly see that the shot is the same one they used earlier in the movie. The water from the waterfall now is going up the cliff! They have just put it in reverse.
Revealing mistake: When Sarah is making her way to the baby Stego, just before she gets on her belly and crawls closer to it, you can see the kneepads she has on.
Revealing mistake: At the end of the Sub-Zero vs Scorpion fight, Liu Kang jumps over to help Sub-Zero and Scorpion teleports away. A few moments later you see a shot where you see all the actors, (Liu Kang, Sub-Zero and Kitana), if you look closely you can see Scorpion waiting in the background just waiting to pop up and snatch Kitana.
Revealing mistake: Right after they "create" Leeloo and she is lying in the plastic cage with the little straps on her, the guy approaches her and says, "if you want out, you are going to have to work on your communication skills." She gives him a dirty look, and then you can see a huge hole, pre-cut in the glass, that she busts her hand through. (00:29:47)
Revealing mistake: In the scene with the helicopter chasing them down the street, apart from the fact that the rotors should catch on something and hurl the machine into a wall, when it finally hits the wall at the end, the pilot and crew quite clearly become about 4 crash-test dummies. This wouldn't be so bad if it weren't for the fact that they are unpainted and all sit in their seats looking straight ahead with their hands in their laps while they are driven into a wall. You'd think they could have at least posed the arms over their faces or SOMETHING!
Revealing mistake: When they are learning how to throw knives, the guy gets one thrown through his hand. If you watch this carefully, blood starts coming out of his hand before the knife hits. (00:28:45)
Revealing mistake: The whole time during the president's escape from AF1 (the scene where he's fighting with his corrupt agent) you can see through the airplane door that there is a loop in the movement of the water. It moves for about a second, and then stops, etc., etc.
Revealing mistake: When Hillard throws the basketball at Ripley, you can clearly see the white tape on Ripley's hand which was used to catch the ball. (00:23:10)
Revealing mistake: Though it may be a little hard to see, when Poe is in his prison cell towards the beginning, he is doing handstand pushups. This would be really cool to see a star doing these only, you can see the strap around his foot holding him up. (00:07:25)
Revealing mistake: When Garfield shoots an arrow at Cesar you can see stuffed padding under his sweater.
Revealing mistake: In the big speedboat scene near the end, when Cage is hanging off the side of the boat the stunt double is obvious in wide shots, where the entire boat is visible from above. He has big long sideburns, which are in stark contrast to Cage's short hair, visible in closer shots. At various other points in the movie, stunt doubles appear of much different physical builds than the two actors, with markedly different hair colours, and I seem to recall that at least one of them had facial hair.
Revealing mistake: When Ellie is traveling through space, she unbuckles herself from the chair to retrieve the compass. The chair then breaks off from the violent movements of the space pod, and slams up against the ceiling. At this moment, Ellie is in deep space in a completely weightless environment. She is floating, suspended in the pod and the chair itself floats a bit before being slammed upwards by the force of the pod movement. But, some small parts of the chair (bolts, etc.) are seen falling directly down, towards us in obvious full gravity; revealing that the scene was actually shot in normal gravity.
Revealing mistake: When Franklin leaps out of the helicopter into the water, there is a shot from above that we see he is about to hit the water. To the left of him in the water you can see the water being split by a helicopter close to the water. The waves wouldn't have been created from the helicopter he just jumped out of because, a)The helicopter was too high up to make that sort of marking in the water and b)The waves are being made to the left of the helicopter. If it was the helicopter Franklin jumped from the markings on the water would have be directly below him or below the helicopter.