Revealing mistake: At the start, when Data is being pulled towards the chained orange drum, due to the angle of the close-up, we see that the soles of Data's Nikes are not actually touching the ground (since there is a rolling mechanism under his feet). Despite the fact that Data is quite inventive, we see in the next shot there's nothing attached to Data's Nikes. (00:03:55)Super Grover
Revealing mistake: When the cook's body is lowered to the kitchen floor, you can see her move her outstretched arm closer to her head.
Revealing mistake: When the pancakes are sticking to the ceiling, you can see that when one hits the ceiling, it jumps. The pancakes were actually being dropped on the floor with an upside down shot. (00:05:45)
Revealing mistake: When Gary and Wyatt come home and see Chet turned into a pile of poo, Chet shoots his tongue from his mouth and catches a fly. Look closely, the tongue flies completely out of his mouth and is attached to a metal spring. (01:24:55)
Revealing mistake: After the cowboys have terrorized the village at the beginning, the girl finds her dead dog and starts crying, when she picks it up it's painfully obvious it's a stuffed toy.
Revealing mistake: Take a good look at the lower right corner during the 'Hearts on Fire' training sequence at a barn in Russia. Rocky does a few leaning sit-ups; at that moment the cow in the lower right corner moves backwards. When you look closely you'll see it moves back too quick and anatomically incorrect, thus revealing it's a fake head attached to wheels or something. (00:57:45)
Revealing mistake: During the scene when Audrey is having a nightmare about eating too much while on vacation, the nightmare ends with her inflating like a balloon from all the food. Her blouse splits open and down the middle, where the buttons have broken, the dark balloon used for the effect is visible. (00:16:35)
Revealing mistake: When Lowry first arrives at Buttle's flat to return the cheque, he hears a cough and turns to see a man smoking a cigarette, half hidden by a column. When he blows a cloud of smoke it is easy to see that it comes from a tube next to his mouth. He isn't even exhaling at the time.
Revealing mistake: In a scene towards the end, we see a crowd of Vietnamese on a riverbank firing their machine guns into the trees...one soldier clearly walks directly in front of another soldier who continues firing away without hitting him.
Revealing mistake: When Hightower throws the football to the hood, the hood flies back to hit the door. After he hits it, you can see the black wire that pulled him.