Character mistake: When Sir informs Kelly that she made the drill team, he says Captain Rigby instead of Major Rigby.
Character mistake: When Stuart calls home from the pay phone he's talking into the wrong end of the phone.
Character mistake: In the scene where Steve and Josie prepare to leave to fight the giant robot at the beginning of the movie, Steve tells Will "Oh, Will, a reminder: a lot of the kids at Sky High will only have one super hero parent, not two." When he says "one super hero parent", he holds up two fingers. When he says "not two", he holds up only one finger.
Character mistake: One of the other trainers said he rode over on a Pidgeotto, but it was a Pidgeot.
Character mistake: When Greg reads the article about L'il Cutie being cancelled, cartoonist is misspelled cartoonish. The article also repeats the first column word for word in the third column.
Character mistake: After Spike comes out of the evolution device, he asks Iggy "Do you know what the square root of 26481 is?" And then answers "191". 191 squared is actually 36481. (00:47:20)
Character mistake: When Wood is telling Harry the rules of Quidditch he says that if you catch the Snitch the game is over, which is true. But then he also says that which ever seeker catches the snitch, their team wins, but that isn't true. Granted that the 150 extra points probably would give you the winning lead, but as JKR pointed out in the 4th book at the Quidditch World Cup, you can catch the Snitch but lose the match. And you'd think explaining the rules to a first-timer you would want to get it right. (01:05:40)
Character mistake: When Stan inflates himself, Michael asks, "How'd he do that?", implying that he doesn't know the rules of the Looney Tunes world. Since Michael was rolled into a ball by the aliens earlier in the film, this shouldn't be too much of a surprise.
Suggested correction: When Michael was rolled into a ball, he wasn't concerned with how that was possible and soon after he forgot about it. He was more concerned with dealing with the Monstars at the time and, in particular, helping his cartoon friends preparing for the game. When Michael witnessed Stan being flattened and inflated, it looked particularly strange and unfamiliar to him, unlike before as he couldn't watch himself experiencing being rolled into a ball. And that is what triggered his response about questioning how it was possible.
Character mistake: When the Grand High Witch and her assistant enter her room while Luke gets the formula, they're wearing pointy shoes. Earlier, it was mentioned that witches never wear pointy shoes.
Character mistake: Chad actually steps on first base before the baseman has the ball. He was safe.
Character mistake: In the beginning of the film, Oliver has been brought by Mr. and Mrs. Bumble to the Governor's door after asking for more to eat. Mrs. Bumble then sings, "They'll lay the blame on the one who named him," and as Mr. Bumble is responding, "O-li-ver", look at Oliver. He is completely spacing out and not in character at all - staring off into the distance and flicking his tongue in and out of his mouth.
Character mistake: Towards the end of the movie when Tim Allen is on the roof and the fire squad is called. One of the firemen carrying the ladder accidentally hits a man in the head with it.
Character mistake: Before the Megarace, Rez looks back at the camera and says that they'll try to help him out-but you can see Juni's tires in front of Rez's car. In a shot before this one, Rez says Arnold will crush Juni-looking at the camera, which is in front of Rez.
Character mistake: In the film, five items are stolen: the Magna Carta, the Turin Shroud, the Imperial Sword of Japan, the Pope's ring and the Pink Panther diamond. When Alfred Molina's character is challenged that they had found everything but the Pink Panther, he protests that 3 out of 4 is not bad, that's 75%. In fact, they had found 4 out of 5 or 80%.
Character mistake: When Casey is using her knowledge of physics to advise a figure skater, she states, "Pull your arms in real tight. That increases your moment of inertia". In fact, this is the exact opposite of how it really works. Reducing her overall radius makes her rotational inertia smaller. (00:21:05)
Character mistake: When Mr Maddens is talking to the critic at the Mayor's reception, he calls him Alan. The character is actually called Patrick Burns, Alan is the actor's name.
Character mistake: In the scene where the photos of Daphne are flashing by, you see her in a photograph which was supposedly taken at the Chelsea Charity Auction. In the caption, "auction" is incorrectly spelled "aution."
Character mistake: In the sequence when Tom is on the phone trying to find a babysitter, he repeatedly says he needs a babysitter for 12 children. However, Charlie, Lorraine and Nora, who does not even live at home, are much too old to need a babysitter. (00:50:45 - 00:51:25)
Character mistake: When Doc and Marty are driving on the Sky Way Doc says "damn this traffic," but in the reflection of the DeLorean's front window there are no cars.
Character mistake: At the FBI facility, Agent 11's handler buckles the collar on the dog's neck. Later, when Gordon has put the collar on and tries to get it off, he's trying to pry it off. He just buckled it on not two minutes earlier. He's stupid, but not that stupid.