Revealing mistake: When Augustus is leaving the factory, he is wearing a brown colored glove on the hand he gnaws on. You can see the seams in the glove.
Revealing mistake: When Shane is fighting the two ninjas, they are armed with expandable batons, which are tubular hardened steel. During the fight sequences you can see the plastic batons bending repeatedly.
Revealing mistake: Even though Drillbit's pinkie was supposedly cut off by the sword, you can see it is just bent out of sight.
Revealing mistake: When the megalodon attacks the yacht the party goers jump off the yacht, and some of them reach the large round safety raft. To the raft's right, there is a visible yellow line attached to it so it doesn't drift away for the shots.
Revealing mistake: While the guys are going for their physicals, there's a scene in which blood is drawn and you can clearly see the tube connected to the end of the syringe pumping fake blood into the container.
Revealing mistake: When the TVs explode, the glass is very fake and "cardboardy".
Revealing mistake: When the professor is trying to find the gremlin, he is in the room with the movie playing. The projector that is playing the movie is actually moving backwards. (00:44:35 - 00:47:35)
Revealing mistake: In the part where Amelie gave back the photo album to the bloke in the fun park, when he finally gets to his bike, you can see people in the background staring intently at the filming. (01:12:40)
Revealing mistake: In a scene where Frog is riding with the Bandit, she's resting her head on the center gearshift console. Although they're supposed to be cruising down the road, the automatic transmission shifter is in neutral.
Revealing mistake: In the scene where Chuck finds Bill in the morgue vault listening to the recording of Chuck telling him to shut up, take note of Bill's thumb on the rewind button of the tape recorder. You can hear the tape recorder rewinding to replay the words, "Chuck to remind Bill to SHUT UP" multiple times but Bill's thumb does not move at all until he turns the recorder off. (00:30:00)
Revealing mistake: When "Pop" dies, you can tell he is still breathing, especially if you fast forward the scene. He is just doing it very slowly, but you can see his chest move up and down.
Revealing mistake: In the scene where Jane is trying to run over John with her car, she jumps from the driver's seat while John is in the back of the car. Right before the car crashes through the fence, you see John through the back window. You also see a head in the driver's seat, even though no one is supposed to be driving the car.
Revealing mistake: Doesn't it seem odd to anyone that the crops hadn't been reaped by Thanksgiving in South Dakota?
Revealing mistake: In the scene where Harry and Lloyd first meet by running into each other, when it shows it in slow motion, you can see Lloyd brace for an impact when he's not suppose to know Harry is coming.
Revealing mistake: During the "Mondo Condo" scene, the books and vases on the bookcase seem to be glued on because as the bookcase falls on Arsenio Hall, when the camera shot is in his point of view, nothing falls off as the bookcase hits the ground.
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: At the funeral when Derek is giving the eulogy a tombstone on the right of screen almost falls over in the wind. (00:15:55)
Revealing mistake: When Goldie Hawn pushes Kurt Russell off the boat you can see he has flippers on in the water.
Revealing mistake: Any time that Charlie is kicked by the kangaroo, they show him falling back onto the ground. But, if you look closely, they just used the same shot over and over. The exact same two lines in the dirt are to his left by his head each time.
Revealing mistake: When George Newton comes into the house and it is raining he has an umbrella in his hand. If you look outside his door underneath the balcony it's wet, but further down the path the ground is dry.