Revealing mistake: When Bert is running in the woods, away from the local guys, he rubs blood on a tree to make them believe he ran a certain way. Look close, the tree already has red tint on it probably from previous takes that didn't wash off. (01:04:35)
Revealing mistake: The scene of rioting in the UK features a load of police officers running through a crowd. All the officers shown are wearing black tunics and custodian helmets worn with chinstraps. This is obviously old stock footage from a protest in the 80's or early 90's as nowadays, (and especially in 2012) the tunic has not been worn as general wear for well over 15 years, and Brit cops are now better equipped for protests with body armour, NATO helmets, flame retardant overalls, etc.
Revealing mistake: When the shark bursts through the window of the cabin, in each of the shots facing Brody, including when he shoves the air tank into the shark's mouth, the glistening water is visible in the window's reflection behind Brody. The shark's reflection is never seen behind Brody, despite the shark's massive size in the small cabin. Bruce must have had the day off during Roy Scheider's takes. (01:58:00)
Revealing mistake: In the library scene when Richie sees Pennywise the clown, all the balloons filled with blood are popping on people who aren't supposed to be able to see them, but one lands on a lady and you can see her jump as the balloon pops.
Revealing mistake: When the terrorists drop the dead body out the aircraft door, look closely at the aeroplane just beneath the door, you can see the reflection of the mat the stuntman lands on, as well as the spotters around it.
Revealing mistake: While Bishop and Steve McKenna are practicing with various firearms, a slow-motion shot in the film of Steve shooting a .50 caliber rifle shows that, while the sequence depicts him firing "live" rounds, the extracted shell casing is from a "Blank" cartridge (evidenced by the crimped forward portion of the brass casing). (00:34:15)
Revealing mistake: In the visions of Nefertiri scene where Nefertiri is fighting Anck-su-Namun back in ancient Egypt, Evie (Nefertiri) gets knocked to the floor and when she lifts her mask up you can see on her right index finger is a band aid/plaster. Did they have plasters back in ancient times? (01:07:49)
Revealing mistake: The Senator's Corvette explodes before it hits the ground. (00:09:10)
Revealing mistake: When the huge alien ship settles over the White House there is an exterior wideshot of the grounds. At the bottom of this shot it's funny how there are many tourists - adults and children, just milling around in front of the gate and across the street with a van driving along between the two sides, and not one has any sort of reaction to the alien ship. This real shot of the White House (some shots had smaller-scale models) had the CG ship edited in during post production. (Visible on fullscreen DVD.)
Revealing mistake: There is a shot from the Terminator's POV, before he rams the blue car with the semi truck, in which you can see that the car is already damaged. No slow-mo is required to see this, but it is a blink-and-you'll-miss-it shot.
Revealing mistake: When Inigo and Westley are duelling, they are making athletic jumps. One does it after the other and when they land you can see the mat wrinkle under the "dirt" on the ground.
Revealing mistake: When John Cusack is driving the actress, there is a shot looking over his right shoulder at the dashboard. The speedometer reads 0 mph. (00:08:15)
Revealing mistake: When Captain Needa is killed by Darth Vader because they lost track of the Millennium Falcon, in the background, two guards come to take him away. You can clearly see the dead captain get up almost by himself. (01:10:50)
Revealing mistake: When Charley stabs Dandridge in the hand with his pencil, he stabs the hand holding him by the neck. The depth of the wound on Dandridge's hand reveals that the pencil should have stabbed Charlie in his neck and given him a severe wound, if not kill him.
Revealing mistake: In the scene where Doc Brown is following Biff into the tunnel, as Marty starts to pass between the cars on his hoverboard, one of the wheels on the rig supporting the hovering DeLorean is visible. (01:30:30)
Revealing mistake: When Batman places the heaters around the telescope to thaw the ice, the frozen floor moves like plastic when he places the second heater. (01:45:00)
Revealing mistake: In the end when Mulder is reading the paper in the park. The paper is clearly a prop. Only the frontpage is real - when he puts the paper away you can see that the rest of the paper consists of blank pages. (01:45:45)
Revealing mistake: When Eric Matthews is smashing his foot, he hits it the first time and it shows a close up. If you watch the small amount of blood when he hits it again they have used the same shot. (00:04:00)
Revealing mistake: When the shark first attacks and bites off Jim's arm, you can briefly see his real arm under his shirt as he's screaming in pain. (00:34:10)
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.