Revealing mistake: In the beginning, during the riot outbreak, there is a scene with a soldier being pulled down from climbing a fence. In the next shot as the crowd is pushing forward, you can see a concrete road block tip over. If you look closely at the bottom of the block, you can see that it's not a real concrete block, but a prop made of wood planks and grey painted rubber.
Revealing mistake: When the Hulk walks through the stream, the water doesn't react to his feet. (00:59:20)
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: Some of the shots involving the terrorists firing at the prototype suit are "flipped" duplicates of other shots. In the scene where he first emerges from the cave, several of the terrorists are firing M4-type rifles with the ejection port on the LEFT side of the rifle. In reality, except for a few specially made versions, all M4-types eject spent brass through an ejection port on the right. Later in the scene, this shot is repeated, but with the proper orientation.
Revealing mistake: When the cop makes a mold of Dave's face from the impact site, there are nostrils in the mold, which are not possible to make with such an imprint.
Revealing mistake: When the guys are heading to the vortex in the cart, you can see the tracks from the previous takes imprinted in the grass.
Revealing mistake: When the guys are seen piloting the UAV's, they are using Saitek X52 Pro joysticks. These are commercially available controllers for Microsoft Flight Simulator. These were obviously used as props. Even if the army did use these for some reason, they weren't turned on in the movie (the buttons glow green when turned on).
Revealing mistake: When the Dreadnought blows up the Buick Riviera, it's plain to see there is no engine or transmission in the car when it flips up and forward.
Revealing mistake: When the double-decker bus flips over Roland, the bus has no passengers and the driver looks very much like a dummy.
Revealing mistake: After Trevor has been lowered above the pit of magma, in an attempt to light the magnesium walls with a flare, we see shots of Sean hanging over the edge of the inside of the T-Rex skull. Sean's hands are resting on a large tooth in the skull, which clearly shakes like a fake prop each time he touches it. (01:17:15)
Revealing mistake: Throughout the Demolition Derby, most of the people in the audience are drawn without faces.
Revealing mistake: When Leela brings soup to Zap and Amy in bed. Leela is wrapped up by a tentacle. The animator forgot to erase the lines of the tentacle as it overlaps. A huge graphical error can be seen.
Revealing mistake: The El Camino that is going over the cliff, which has just been shot in the tailgate with a 50 caliber rifle, has no tailgate damage. Also at the same time stamp, when the El Camino is upside down, it is obvious there is no transmission or drive shaft in the car. They even show you this with a close-up. (00:46:20)
Revealing mistake: As Rob, Hud, and Lily are rescuing Beth from her apartment, the view outside the window is tilted roughly 45°. This is due to Beth's apartment building being partially collapsed against another building, demonstrated previously by an exterior shot. However, the characters are moving within the apartment with no difficulty or apparent change in gravity, even though they should be struggling to remain upright in a significantly tilted apartment. This makes it clear that the scene outside has been added using chroma key technology, and the camera has simply been tilted to create the illusion that they are on an angle. (01:01:30 - 01:01:52)
Revealing mistake: When Anakin, Ahsoka, and the clones begin their ascent to the monastery on planet Teth, the ascension cable of one clone trooper (second from the front when the shot begins) is not animated correctly and a gap can be seen between the end of the cable and the clone's blaster. (00:35:35)