Revealing mistake: When Neil is teaching Yoga exercises to the elves a first close up shot of one of the elves (the Asian looking one) shows he doesn't have pointed ears like the rest in the group.
Revealing mistake: At the end of the movie when the cheer squad is shooting the video with Rhianna, she is wearing a blue shirt. The shots cut back and forth between the reality of them shooting the video in front of a blue screen and what the video looks like with the effects. If Rhianna is wearing a blue shirt and is filming this on a blue screen, she would appear to have no body when no one is behind her.
Revealing mistake: When the canoe is speeding down the hill, there's one scene where you can see there's already a groove in the snow from where they did a previous take.
Revealing mistake: As Clouseau falls down the stairs when pretending to read the newspaper, you can see his legs flick up after he has supposedly fallen beyond sight - indicating he fell onto a mattress just below the camera's view.
Revealing mistake: Near the end of the movie, when Starla is flung about by Grant, in some shots it is obvious that Starla is replaced with a stunt double, as there is a noticeable hair change in some of these shots.
Revealing mistake: When the Quickstop burns down in the beginning, you can easily tell the fire has been added with computer graphics, as it appears very flat, and some even has a slight blue haze around the outside, where a little bit of the blue screen "bled through."
Revealing mistake: Near the end of the film when Amanda and Dr. P almost take off together, there is a shot of them boarding. Look to the top right corner of the screen and for just a split second, you can see a glimpse of Roger chasing after them, along with Amanda's facial expression turn shocked. I'm pretty sure this happens because in the alternate ending Roger caught them when they were boarding.
Revealing mistake: Just after Boog breaks the dam and the deer herd is bounding across the dry riverbed, at the moment they realize they are going to be swept downstream by the wall of water, their legs disappear - just left out of the animation cell. Very obvious; no slow-mo needed to see.
Revealing mistake: In the scene where Luigi offers his service to Van and Minny, Guido is juggling wheels. But when Guido finishes, you can see over his right lift that his one of his wheels is not rendered correctly, as it seems to overstep his bodywork.
Revealing mistake: When Stewart is working on his laptop at the satellite dishes, it is very obvious that he cannot type. He is tapping the keyboard repeatedly with several fingers, without moving his hands. (01:18:40)
Revealing mistake: When David Arquette is preparing to drive his rocket car, he does a u-turn to get pointed in the correct direction (towards his friend who is filming). The image is reversed at that point, so that he appears to be driving from the passenger side of the car.
Revealing mistake: When Stella the skunk yells at the cat, she pokes him on the face. However, you will notice that the hand looks a lot like a human hand, not Stella's.
Revealing mistake: The reaction of the jogger being hit by Clark's bat is way too late.
Revealing mistake: When the American man throws a square concrete tile at the monster it reacts (moves its foot in pain) before the tile actually makes contact. (00:16:11)
Revealing mistake: In the badminton scene when Sadie flashes her breasts, her chest and abdomen are much more tanned than her hands and face are. The makeup people didn't match up the body double's skin tone to the actress'.
Revealing mistake: At one point in Heat Miser's song, he eats two fireballs. Directly above the second fireball you can see the reflection of string used to hold it up.
Revealing mistake: When Michael fast forwards through traffic for the very first time, right before he hits the slo-mo button on the female jogger, if you look inside the circle part of the remote, the graphics are missing.
Revealing mistake: Throughout the scene when it is revealed that Jack has been offered a six month trial with the local team, the wall clock is stuck at the same minute and second. (00:18:30)