Revealing mistake: When Babs is writing down what is said during the fraternity's disciplinary hearing (court reporting), no ink is actually coming out of her pen as she writes on her notepad. In fact, the notepad remains blank even as she turns to a new page while still writing. (01:04:50 - 01:05:55)
Continuity mistake: During the parade scene at the end of the movie, there are shots of the street that it will take place on, and there is a view of a (misspelled) "Homestead Ferniture" store in two different shots. When the parade is actually taking place, the store is changed to (correctly spelled) "Homestead Furniture". Several shots after that, it changes back to "Homestead Ferniture" (01:33:20 - 01:44:00)
Continuity mistake: During the parade, Flounder dumps the bucket of marbles towards the camera, and they are all clear glass marbles. When the ROTC members slip and fall on them, the marbles are red, blue and yellow. (01:38:25)
Continuity mistake: When Pinto and Flounder attend the Omega rush party, a tasteful piano piece is playing. Niedermayer catches the eye of the brother at the piano, who smiles back over the keyboard. Soon thereafter, Niedermayer points out two important Omega brothers, who are standing in conversation across the room: Terry Auerbach, captain of the swim team, and Carl Phillips, editor of the Daily Faberian. The music has not stopped, but, when Carl turns to the camera, we see that he's the same guy who's supposed to be playing the piano. (00:03:15 - 00:04:55)
Revealing mistake: On the day the house is being emptied, after Bluto finishes the Jack Daniel's and tosses the bottle, there are no Jack Daniel's labels on it. (01:07:35)
Visible crew/equipment: During the scene where Otter is hitting golf balls at the ROTC cadets, Niedermayer is wearing a highly polished chrome helmet. In at least one shot, you can see a movie light reflected in it. (00:20:10)
Continuity mistake: When they show Flounder's face on the screen they throw beer cans at it and it gets soaked. When Otter gets up it is completely dry. (00:13:55)
Revealing mistake: When the people from the grandstand are flying up in the air after the Deathmobile hits it, you can tell they used a trampoline to get the effect as the woman are in their stocking feet; it would have been a safety issue if they jumped in high heels.
Continuity mistake: When Neidermeyer is yelling at Flounder about his pledge pin, Neidermeyer is spitting the P's in Flounder's face. When this happens, the camera is on Neidermeyer and if you look at Flounder, (even though it's his backside), you can see his eyes close everytime he's spitted on. However, afterwards, the camera changes to Flounder instantly, and his eyes are wide open (as if they never closed at all). Nobody's eyes instantly open THAT quickly after being spat on.
Audio problem: When D-Day, Bluto and Flounder are running out of Wormer's office after the horse died, there is a sound effect of them screaming as they flee the scene. This exact same sound effect is used when the boys run out of the all-black bar, except Bluto and D-Day weren't there; it was Flounder, Kroger and Boon. (00:30:40 - 01:17:15)
Continuity mistake: As Niedermeyer chews out Flounder in the close ups, the long shots from Boon and Stratton's view of the action shows Niedermeyer mounted on his horse, then back to the close up of Niedermeyer dismounted, continuing to chew out Flounder.
Factual error: At the end of the movie when the riot is taking place, Niedermeyer takes out a bullet and fires upon Flounder from maybe ten feet away and misses - all the bullet does is shatter the seltzer bottle and nothing else. Whether Niedermeyer meant to miss Flounder or not, the bullet would have shattered the bottle with little or no deformation to the bullet itself and would have hit the pedestrian running behind Flounder.
Continuity mistake: In the cafeteria "I'm a zit" scene, Bluto picks up the mashed potatoes with his right hand, but the very next shot shows him placing it in his mouth with his left hand. (00:34:50)
Revealing mistake: You can see that the Jack Daniels that Bluto chugs is not real, because it foams. It was probably iced tea or something. (01:07:30)
Continuity mistake: From Double Secret Probation DVD - "When Bluto is placing the ladder outside the sorority house, there is a large awning between the two windows and it would be impossible for him to "jump" the ladder from one window to the next." (00:38:29)
Audio problem: When Bluto is using the ladder to look in the sorority house, the ladder gives a clanging sound like an aluminum extension ladder. The ladder Bluto is using is a single frame wooden ladder which wouldn't make any clanging sounds at all.
Continuity mistake: When Pinto and Flounder visit the Omega house in the opening of the movie, notice the girls coming down the stairs. In the first shot they are there, the second shot they are not, then they are. (00:03:00)
Factual error: Listen to the crickets chirping at the football field where Larry and the Mayor's daughter make love. It's fall, everyone has jackets on. It's much too cold for crickets to chirp that rapidly. (Or at all at that time of year). (01:32:00)
Factual error: Mrs. Wormer confuses the meanings of "sensual" and "sensuous". Sensuous merely means appealing to the senses; sensual has sexual connotations. In other words, vegetables are sensuous; people are sensual. (00:46:45)
Continuity mistake: After Stork pushes the drum major off camera to the right and seizes his baton, the scene cuts to a longer shot where he leads the band in the same direction. The drum major has disappeared. (01:36:30)
Answer: Sometimes these things get left in because it's simply the best take. (The child covering his ears before the gunshot in "North by Northwest," for example.) It could also be that John Landis cast the extra because he wanted someone with goofy expressions in the crowd. He simply could have told the extras "Ok, be excited that you're at a parade," and that's how this extra did it.
Captain Defenestrator