Revealing mistake: The final scene is filmed in Brant Rock MA, and the weather is blatantly CGI. If you notice almost everyone is bone dry in a supposed driving rain storm. Look especially at the character perched on top of the submarine tower. For contrast note the "pizza delivery" scene where it is raining heavily and everyone involved is soaking wet.
Revealing mistake: In one of the final scenes where Stallone is hanging out of the Statue of Liberty, you can see that his "JUSTICE TATTOO" on his upper arm is a fake. You can see at the edge of the tattoo that it is glued on the skin.
Revealing mistake: When the Hulk walks through the stream, the water doesn't react to his feet. (00:59:20)
Revealing mistake: When Wick is rubbing his toeless feet, the shot changes so that the camera is behind him and you can see him still rubbing except now you can see that he is simply curling his toes over.
Revealing mistake: In one scene, the Penguin is making a "bat" shadow puppet on the ceiling. But there's no light behind his hands. If there's no light, there's no shadow. (01:03:45)
Revealing mistake: Near the end of the film, after the shootout, there's a shot with the camera zooming in on a newspaper at Will Smith's front door. If you pause it right once the headline fills the top of the screen, you'll notice all the paragraphs are just repeated, word for word. Additionally the word "received" is misspelled.
Revealing mistake: Just after Li Mu Bai tells Shu Lien that they are very close to her headquarters and that she should check in, we are treated to two 'time pass' shots of forest. The second of these features some very obvious power or telephone lines in the lower right corner of the screen. (01:22:40)
Revealing mistake: When the Muslim emissary arrives to Jerusalem and Guy de Lusignan stabs him under the chin, look at the blood. It bursts from something attached to his shoulder. In addition, the emissary is seen as stabbed with a small dagger but then Guy De Lusignan is shown holding a full length blood tipped sword a second later.
Revealing mistake: When it shows the video of Tom Cruise on Youtube, on the right side of the screen, the descriptions of the other videos repeat themselves.
Revealing mistake: When Barb is in the bubble bath, you can see the strap from a G-string she is wearing.
Revealing mistake: At the Smithsonian Air and Space Museum, there is a triangular enclosure around Jetfire that amusingly just fades away and vanishes as Jetfire transforms. (01:23:05)
Revealing mistake: When Blackout is destroying the base in Qatar, a few Humvees get flipped over, and none of them have engines in them. (00:07:00)
Revealing mistake: In Houston, when a man is thrown through a truck, notice the ground he falls on: The sand is leveled higher than the rest of the road around, obviously to hide a landing mat. Furthermore, after the fall the man turns around and he's got a bulgy square on the back to help for a safe stunt.
Revealing mistake: In the New York meteor shower scene, most of the cars blow up without having been hit at all.
Revealing mistake: When the sheriff's car is flipped upside down, the sign behind the car is upside down too, so you can tell the car isn't really upside down.
Revealing mistake: When Montoya uses a spear to toss the vampire woman from the prison door into the sunlit street, it is an obvious dummy that has been used. First you see the woman stumble out, and the first flames shoot out of her, then the angle changes to a close-up of her as she is engulfed in fire. In the close-up, she has become bigger and rounder, and does not move.
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 Jack is hanging out of the truck you can see him standing on the hood of the car which Lydia is driving. At some points we get camera view from the back seat of the car. In some angles the mirror inside the car disappear. This is to prevent us from seeing the camera. (01:04:15)
Revealing mistake: When Benjamin and Harry are talking on the steps of the legislature of Charlestown after deciding to go on war with the British, you can see a man behind them with something in his ear, a hearing aid or earpiece. (00:16:30)
Revealing mistake: When Damoscinos is dying, just after being bitten, he stumbles to the ground. As he does so, you can see the tube feeding the green "blood" to his neck on the ground behind him.