The KOK alumni that are shown throughout the movie mainly consist of fraternity members from Animal House (1978). There's also a cameo by John Vernon as a nursing home patient, better known as Dean Wormer from Animal House.
'Michael Rosenbaum' wore a wig throughout the film, as his television role on Smallville (2001) required him to keep a bald head. Rosenbaum said that if he was going to wear a wig, he wanted it to be a bad one, thus the ugly hair Adam sports in this movie.
When Adam tries to seduce Jimmy in his room and begins screaming for Dave's help, the shot is from outside looking in through a seemingly broken window. However, when we see the inside of the room, the windows are intact. They're only broken after Jimmy is thrown out of them, not before.
During the DOG/Tri Pi. Football game, the scene opens with the girls getting ready to play, they show the Tri pis warming up during a foggy morning, the dogs warm up in the sunshine and the referee calls the teams during the late afternoon.
When the boys join the D.O.G house, you see everyone in a circle with food in the middle. When they go around and introduce themselves and it comes to Patty's turn, she says "I'm a very gentle person" and puts a mug to her mouth, accidentally breaking it. Nothing comes out of the mug, and if she went to drink something, wouldn't it all spill out when she broke the mug?