Continuity mistake: When Martha Johnstone falls on Justin during the cheerleading tryouts, her skirt falls up and is laying on her back; they show this in a front view; but when they switch to a side view, her skirt is back down covering her bottom. (00:06:35)
Continuity mistake: When Lindsey is at her parent's house during spring break, they are discussing her father's hair. In the shot when her mother opens the fridge there are only 5 cookies on the plate, but when the shot changes and Lindsey is grabbing some cookies there is a whole plate of them. And the honey pot is missing too. (00:30:30)
Deliberate mistake: At the start of the film when the commentators are explaining the tie situation between the 3 cars the green arrow to the car is out of alignment and misses the car, instead pointing at the track. Pixar Creative Director, Jay Ward, who is this film's team manager (as well as art coordinator) has stated that this was deliberately done as a joke, for fun. It's a little bit off, in the same way that Chick Hicks is a little bit off. This is the video with Jay Ward explaining: https://youtu.be/ZkJre-eC-zE?t=25.
Continuity mistake: In the scene where Chazz and Jimmy are talking about Chazz's shampoo, Mane & Tail, Jimmy puts the bottle on top of the bed post. When Jimmy turns away, the bottle is gone. Immediately before he turns, the top of the bottle was visible. (00:32:10)
Continuity mistake: When Happy and his Grandmother arrive at the nursing home, Happy puts his Grandmother's suitcase under the bed. In the next shot it's not there anymore. (00:09:45)
Continuity mistake: When Boobie gets in the car after clearing out his locker the car window is very dirty and spotted, but a few seconds later the camera shows the window again and it is perfectly clean and spotless. (01:11:45)
Continuity mistake: When Russell Crowe first pulls in front of Hank Azaria his car's quite angled on the road as he gets out. When we see a wide shot after they finish talking, the car's now much straighter without anyone having gone near it.
Continuity mistake: When Rocky is carrying Adrian home after their wedding, Adrian is still wearing her bridal veil cap and we see the lace design closeup, but when they're inside the apartment Adrian is wearing an entirely different veil cap.
Continuity mistake: When Adam Sandler reverses into the police car, he damages the Bentley he is driving at the back end. When the police chase him, the back end is not damaged at all. (00:06:35)
Continuity mistake: At the end, when they are celebrating, Wesley Snipes jumps into a player's arms. his helmet is on then knocked off but back on again in the next shot. (01:39:05)
Continuity mistake: In the scene when Jack Black is about to be unmasked and the kids are watching his match on TV, Chancho goes to to cover the TV. He is wearing a pink shirt but in the shot of him covering the TV he is wearing a white singlet.
Continuity mistake: When Marni writes "BETTER" on the whiteboard, the handwriting changes between shots.
Continuity mistake: We first see from the inside of the door (and therefore backwards) the instructions that Mr. Miyagi leaves for Daniel to paint the house. In the next shot we see the same note from the outside - from Daniel's viewpoint. Clearly they are two different notes. The left & right arrows switch directions, the drawings of the hands change, the position of Miyagi's signature changes, and the placement of some of the exclamation points changes.
Continuity mistake: The fan who came out onto the ice and draped a flag around Jim Craig's shoulders (a cameo by the film's director, by the way) put it on upside-down. The camera cuts away, then cuts back, and it's suddenly right-side up.
Continuity mistake: When the Rad Pack first meets and are skiing together, Dan O'Callahan is wearing a blue baseball cap and sunglasses. In some later shots he is wearing a stocking cap and goggles. (00:31:25 - 00:32:00)
Other mistake: Near the end of the closing credits, when the Warner Bros. Copyright appears, you'll see the very first word "All" spelled incorrectly as "Al" in "All material is protected by Copyright Laws of the United States and other countries throughout the world." (01:26:40)
Continuity mistake: In a couple of close up head shots of Paul Bettany in the final match, the tag in his shirt is visible. In one shot the size of the t-shirt is L (large), in a later shot within the same scene it says M (medium).
Visible crew/equipment: During the final fight, a steady cam operator with a white shirt and black straps around his body is seen during several wide angles. This is not a TV camera, it is a film crewmember. The Director even admits to it in the audio commentary on the DVD.
Deliberate mistake: While Donnie is training at Front Street Gym, when Rocky repeats, "One step at a time, one punch at a time, one round at a time," the closeup of two children watching from outside the ring is a flipped shot, note the backwards Nike swoosh logo and Everlast ring rope spacer. (00:53:05)
Other mistake: The Jackson High Cougars goat mascot that McGrath must return is played by two different goats; note the goat's distinctive horns change, and its bell collar is buckled the opposite way.