Revealing mistake: When Troy says "I'll sing with her," Ms. Darbus turns around "in response" to his voice before he even says anything.
Revealing mistake: When the driver is taking Amanda to the airport at the end, all the dials on the car are at zero, so obviously the car is not moving at all.
Revealing mistake: When Pintel is running up to Ragetti during Elizabeth's rant on Isle Cruses, you can see the path in the sand where Pintel has run up in previous takes. (01:48:05)
Revealing mistake: In the park after the bad guys have been defeated and everyone starts returning to the museum, watch the T-Rex closely. In the overhead shot, he seemingly "floats" right through the branches of the trees which he normally would be moving. (01:34:50)
Revealing mistake: When Megan peeks through that slot thing at least two of the bad guys look straight at her.
Revealing mistake: When Bob has difficulty with his seat belt at the start of the road trip, the side-view mirrors have a translucent finish, just as in other shots throughout the film; however, the mirrors' surfaces are normal in the rest of the shots. Deliberately done to obscure the reflection of the crew. (00:13:20)
Revealing mistake: Jorge misses scanning the barcode on the tire by several inches at the end of the competition, but it rings up anyway.
Revealing mistake: When Gary and his friend are drinking Bud in the bar, the Bud label moves between shots to keep facing the camera. Gary doesn't touch the bottle.
Revealing mistake: In the scene at Frankie's house, Vanessa panics when she awakens and realizes Frankie and the children are away. When they re-enter, Frankie is heard telling the children that the carton he is carrying is "ice cream for Mommy." Frankie asks to speak with Vanessa in another room and sets the carton on a table. The sound of the connection makes it obvious the carton is completely empty.
Revealing mistake: When Cindy hugs Tom (Charlie Sheen) and the razor blade gets stuck to his chest, the patch the blade is attached to under his shirt is visible. (00:05:45)
Revealing mistake: When Julia does her dance for the firemen, they hit her with the fire hose and she gets knocked back. In a few shots after that, especially in the close-up of her swishing her hair back, you can see on her neck that the neck-fat piece has come loose.
Revealing mistake: You can see Buddy and Finch's stunt doubles in the ice skating scene. And when they are showing a close up of them you can tell that they are not really ice skating, but just doing the ice skating movement.
Revealing mistake: After John and Nelson are led to their prison cell, Nelson walks to the toilet and starts complaining about how disgusting it is. When Nelson steps away from the toilet, he breaks down in tears and let's himself fall backwards against the 'stone' prison wall. The wall is seen moving, which reveals it's not a real stone wall, but made from a softer material, like wood or plastic. (00:25:15)
Revealing mistake: When the dad inserts the rectal thermometer into Calvin and he looks up, the CGI head is too obvious, especially when he is putting his head back down on the bed.
Revealing mistake: When JB and KG are doing the powerslide in the Rock N Roll History Museum, you can see that KG is wearing knee pads to help him slide.
Revealing mistake: In the scene where the grandfather has passed away and the family is at the hospital, there is a shot where the family steals his body and pushes it out a window. At one point in the next shot, when the family is carrying "him" to their van, the sheet moves and it's obvious the cast is carrying a bunch of pillows covered in a sheet. This also is obvious from the ridiculous way the "body" is laying on the bed prior and folds up when the cast picks "him" up and hoists "him" out the window.
Revealing mistake: When Harry Judd drops his drumstick down the trapdoor backstage, watch him carefully - He actually opens his hand and chucks it forward slightly.
Revealing mistake: In a scene where Fido is turned around, you can see a part of his head that is pink. However the rest of his body is grey.
Revealing mistake: When Landfill's wake is knocked over and his body falls on the guy, his eyes are open for a second or two before the scene ends.
Revealing mistake: When Bobby is being chased by the police in his Dad's car it is blatantly obvious that a stunt double is driving.