Revealing mistake: When the taxi goes over the edge to capture Dr. Neville, you can see that the underbody of the car as it goes over is a flat painted surface and not the underside of what should be there (i.e., muffler, gas tank, etc.).
Revealing mistake: Underdog's first costume is supposed to be a felted down (the more accurate term would be fulled) wool sweater. When wool is felted the stitches lose clear definition and usually achieve a "felted" look. It is clear that the sweater in the movie has just been switched for another smaller sweater as the stitches are still sharply defined after it has been pulled from the dryer. This is especially clear around the U. No attempt to make the smaller sweater look "felted" was made. This refers to the original costume with the solid white U, not the second costume with the yellow outlined U.
Revealing mistake: As Carlos is giving his final goodbyes to Claire you can see in the background automobiles driving down the freeway. Shouldn't these roads be empty rather than having what seems to be a thriving highway? (01:10:00)
Suggested correction: Not a single car in the background.
Revealing mistake: When Sandman is in the truck of sand and the cop climbs up to catch him, you can see the edge of a platform uncovered. The platform is clearly there so the cop could walk without sinking - he stops right where the platform ends.
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: During the scene where the military loses control of London, and their snipers are told "all targets are free", you can see heavy padding beneath Infected/civilian victims' shirts, etc, as they're shot. Presumably it's to stop them injuring themselves when they fall over, or to hold apparatus for the blood effects, but it's too bulky to be part of the characters' clothing.
Revealing mistake: At the end, there is a group of people with their backs to the camera, facing & waving to the Fantastic 4. As the F4 fly towards the camera and out of the shot, the crowd turns to continue waving to them. One small boy in white remains facing the wrong way, still waving, until another child grabs the back of his clothes & turns him to face the right way.
Suggested correction: Not necessarily a mistake. Little kids can have a hard time keeping track of/focusing on things. I know little kids that have a hard time looking in the direction of the camera when their picture is being taken.
There's a difference between not looking at a camera when you don't care about having your picture taken and being able to follow superheroes that pass you, especially if you're waving at them. The reason it's a revealing mistake is because everyone involved had to pretend superheroes were passing them and the kid didn't know when to turn.
Revealing mistake: When the zombies are eating the intern in the hospital, you can see one of his ribs move as if it were made out of rubber. (00:51:20)
Revealing mistake: Near the end, right when "little wonders" starts, Lewis takes a moment to look at his future family, Lucille, Frannie, etc. When there's a closeup on Lewis, his memory scanner reveals a reflection of no one in the gym, except for Lewis, even though people are supposed to be standing in front of him.
Revealing mistake: When Cris drives his car over the railroad crossing, the CGI locomotive which passes subsequently lacks a fuel tank which is usually between the two sets of wheels.
Revealing mistake: As Lex is walking away from the container that holds Superman's body, the glass of the container is reflected in the floor, as is Superman's body. But the little pedestal that he is hovering above is not reflected. (00:43:30)
Revealing mistake: At the start when the tree falls through the window, it's been pushed through the window horizontally. Since it does no damage around the window as you would certainly expect from a tree falling through an arc. (00:01:20)
Revealing mistake: When everyone is cheering to Bender, you can see Fry on the right hand side of the screen wave to him twice. The second time he cheers, his hands move from the table to suddenly waving at Bender without any animation. (01:19:50)
Revealing mistake: Meatwad and Shake get booted off the computer by Frylock so he can find instructions to the Insane-O-Flex. Watch the computer monitor. It rumbles, but the logo on it stays still.