Deliberate mistake: In the towel-dance scene after Demi has put on her white panties and spins off the towel from her hair she starts to rip off her body towel. Then in the next frame the towel is again tucked in. Apparently they didn't want Demi topless when she leaned over to slip on her blue shorts.
Deliberate mistake: When the Trunchbull is drinking from the glass with the newt in it, you can easily see that she doesn't actually drink anything, as the water level stays exactly the same. Logical, as the newt is real, but it's still very obvious because she drinks for about 15 seconds. (00:46:55)
Deliberate mistake: Practically all movies incorporate the name of the movie within the dialog. However, they must remember the English language and tense agreement. On at least two occasions, Fishburne says "Come on Dodge, lets FLED." If they were so interested in incorporating the name within the script, they should have named the movie FLEE.
Deliberate mistake: When the Looney Tunes are playing basketball against the aliens, if you look in the stands the same cartoon characters are in different places at the same time. This happens a lot.
Deliberate mistake: Just before Donald has a fight with Jack at the end of the film, we see Donald jogging down a flight of stairs to escape the building. Then after a bit of a punch up with Jack, we see Donald running back up the same staircase to escape Jack, but when he reaches the top it turns into a dead end. There is nowhere that Donald could have came from when we see him coming down the stairs. (01:19:35 - 01:20:35)
Deliberate mistake: When Sidney is typing the message to the police, you can see that there are red lights flashing, which must mean the police are there, 5 seconds after she types. Obviously deliberately done for the humor. (00:29:30 - 00:30:25)
Deliberate mistake: In the scene where the boys scratch off the paint on the window so they can look at the ice skaters getting dressed, there's a grille about 6 inches from the window. When viewed from outside their faces are pressed against the grille, but when the shot changes to inside the building looking at their eyes moving, their eyes are much closer to the window than the grille would allow. (00:09:30)
Deliberate mistake: When the media truck follows Mel, he comes to a traffic light and stops. When he throws away the van's keys, he speeds off from the intersection. Why are the cars at his left not driving? They look like they have parked there and with no drivers present in the car. Weird for a very busy road.
Deliberate mistake: In the scene where Joan and the kids pile into the station wagon after Stanley is kidnapped, Joan tells the kids to hold on tight and puts the car into reverse. However, in the matter of seconds that have gone by, Joan hasn't even started the car, yet she was able to put it in reverse and drive off. Even if she had the skills to start it that fast, you would hear the car turn over. The car is never heard turning on.
Deliberate mistake: The disco ball doesn't start reflecting the sunrise until after the lead characters get out, even though it should have began to reflect light right when the door opened.