Revealing mistake: In the David Letterman scenes, Paul Schaeffer's head is shaved, which he just did recently (maybe within the last year to year and a half). (01:15:00)
Revealing mistake: Signs for Baltimore based businesses are clearly visible in the stands, such as "Sheraton Inner Harbour" and various Baltimore banks.
Revealing mistake: When they are all in the camper van Tiffany gives Chucky a biscuit then walks away from him, from the way she gave him the plate, they would have all fallen off. (01:07:35)
Revealing mistake: When Charlie and Grandpa Joe drink the fizzy lifting drink and are floating in the air you can see the hook that is connected to the wire that Charlie is being held up by.
Revealing mistake: In the scene where Joey parks his car behind Kat's you hear him coming up really fast and then you see it stop, but if you look in the window across the street you can see in the reflection that the car was still and then it just moves up a little bit. (00:25:30)
Revealing mistake: In the changing room before the Final, Peter leans against a dark wooden pillar several times. It moves on each occasion.
Revealing mistake: In the dance sequence, we see Elaine twirling Ted around and throwing him into the crowd. Watch the top-right-corner of your screen, as the stunt-double lands in the audience you can see Robert Hays (Ted Striker) in the top-right-corner waiting to pop out. (00:19:10)
Revealing mistake: When the weasels are at Eddie's apartment and Roger is handcuffed to Eddie, Roger runs under the bed and drags Eddie on the floor. As he pulls him you can clearly see a board with wheels under Eddie that is pulling him under the bed. (00:38:50)
Revealing mistake: When the boys' rival team challenges them, all the boys throw their gloves down, except Yeah-Yeah. When they all go to pick them back up, Yeah-Yeah has to pretend to pick it up.
Revealing mistake: When Cody is on the jet ski inside the evil guy's hideout, he smashes through some glass. The glass smashes before the jet ski even touches it.
Revealing mistake: When Bluto is watching the sorority girls have their pillow fight and he falls down with the ladder, you can see him land on a grass mat that is cut into the lawn. It's funny because you can see the grass push in. (00:40:00)
Revealing mistake: When Jake is driving Andrew to Melanie at the battlesite, Jake is driving with the truck in the park position. (01:11:00)
Suggested correction: Or it's a manual 3 speed on the column in 2nd gear while driving slowly through town.
Revealing mistake: When Troy crouches down on the rocks, and leans down to see his reflection in the water, oddly the reflection is not reversed, yet his hair is combed the opposite way. (Did the director actually think that if Troy's hair was combed the opposite way it would pass as a reversed reflection?) Additionally, when he crouches down, the bottom button on Troy's shirt is unbuttoned, but in the reflection (as well as in the previous and following shots) the bottom button is buttoned up.
Revealing mistake: In at least one scene, you can see the ruts that the filmmakers made in the greens to make Happy's putts go where they wanted them to.
Revealing mistake: In the middle of the movie, Roy is flossing his teeth by himself. In the mirror as well as when he turns around, you can see his hand holding the hook, if you look closely. (00:58:33)
Revealing mistake: There is an obvious stunt double for Grandpa during the fight scenes.
Revealing mistake: When Tim Curry runs out of Kevin's hotel room after being scared by the inflatable clown doll he hits his knee on a table. When he hits the table and then hops away you can clearly see that he is wearing a knee-pad.
Revealing mistake: The Aspen lift operators are wearing Copper Mountain uniforms. Copper Mountain is in Colorado, but it is over two hours away from Aspen.
Revealing mistake: When they're dancing on the bowling alleys, they couldn't be waving their bowling balls about as if they were made from foam - bowling balls are heavy!
Suggested correction: Bowling balls can weigh as little as 3 pounds.
Revealing mistake: In the scene with the accident, the car already has bumper damage just before it hits the pole. (00:21:00)