Revealing mistake: When Marin and Jack Nicholson first enter her mother's house, Marin is wearing white pants, and it is noticeable that she has a thong on. When she gets into bed with Jack, she is in full underwear.
Revealing mistake: While Akeem is getting his hair cut, you can see the reflection of the white character he plays in the mirror. It is quite obviously a stand-in, with a fatter face and different glasses. (00:33:45)
Revealing mistake: During the car chase scene, if you watch the speedometer on the car, it never rises above zero. That, and the obviously poor image quality of the "road" in front of them, shows that they were using projected film in front of the car.
Revealing mistake: While Wayne, Diane, Patty, and Gordon are in the laundry basket, Adam and Mitch carry that basket upstairs. When Mitch says, "I bet my parents wish I didn't have a medical problem," the camera turns to follow the boys as they walk up the stairs, and the left wall (with striped wallpaper) of the staircase is missing to accommodate the camera filming from that angle. It's visible again when Mitch says, "And I feel fine." (00:35:35)
Revealing mistake: When Benji imagines putting on a mask of an agent he plans to impersonate, when the camera pans around to first show the mirror, the mirror Benji's hands are further up on his face than the reflection, and the mirror Benji's hands move down his face slightly before the reflection starts to move them. Also, the mole that Ethan has on his left cheek isn't reversed in the mirror image. The "mirror" was actually a hole in the wall between two identical sets (one mirrored), with Simon Pegg and a Tom Cruise double in the foreground, and the mask actor and Tom Cruise in the background "mirror" set. (00:57:20)
Revealing mistake: In the scene where Storm and Nightcrawler rush to rescue the children from the holding cell, you see a shot of the cell where the children stand up and say "Listen..." before Nightcrawler teleports inside. If you look carefully, you will see Nightcrawler's silhouette in the shadow against the wall. (01:27:50)
Revealing mistake: Throughout almost the whole movie Harry's glasses don't have lenses in them. Only in two or so scenes do they appear.
Revealing mistake: In the shooting scene in the Mount Rushmore cafe, a boy in the background puts his fingers in his ears, because he knows the gun is about to be shot.
Revealing mistake: When Scorpion and Johnny Cage are in the forest, you can see a car drive by in the far left corner. You have to look really close though.
Revealing mistake: You can see wires in the scene where Regan levitates above her bed in the exorcism scene, lifting her up. The way they pull on her dress is also visible.
Revealing mistake: When The Mask is dancing with Tina and he turns her into a human tornado while spinning her around, none of the onlookers in the crowd show the slightest bit of amazement at the impossible feat that just occurred in front of them, indicating that the extras were not directed to react to the special effects.
Revealing mistake: When Henry's mom is pushed off the cliff her cable is visible.
Revealing mistake: The ship set up for the capsize scene is supposedly mid channel and heading for England when it is bombed by the Heinkel, but it is at anchor.
Revealing mistake: When all the kids are in the diner just before Chunk knocks over the water jug, Mikey starts to bang on the ground with a bar. When Brand stops him, Mikey calls him by his real name Josh. This is verified on the DVD by Sean Astin himself, in the commentary. (00:40:40)
Revealing mistake: When Sonny is on the payphone, you can see Julian mouthing something to the guy on the payphone behind Adam. The guy is giving him instructions.
Revealing mistake: At the end when Brian jumps onto the semi truck to save Vince if you look closely at the back of Brian's pants you can clearly see the safety cable that holds him onto the semi truck. (01:26:17)
Revealing mistake: In the final game against Iceland scene, there is a point where you can see that the people in the stands are actually cardboard cut-outs.
Revealing mistake: In the scene at the end of the very first battle, where Imperial troops have just taken control of Princess Leia's rebel ship, Darth Vader breaks the neck of the Captain Antilles and tosses his body to the wall. The "dead" Captain puts up both of his hands to avoid slamming his face into the wall. (00:05:40)
Revealing mistake: In the Forbidden Forest, HRH are introduced to Grawp. Just as the giant lifts Hermione off the ground, in the shot from behind her, Hermione's legs disappear below her calves; the digital lines are actually visible. Slow-mo is not necessary. (Only visible on fullscreen DVD.) (01:29:40)
Revealing mistake: Most of the posed, fake displays in the ape's Museum of Natural History contain real people who are slightly moving if one pays careful attention. Especially noticeable are those posing with objects held in - or above - their hands.