When Tom calls Riff from his van, he mentions that he is listening to the "new Ramones album." The song "I Wanna Be Your Boyfriend" can be heard in the background. The problem is "I Wanna Be Your Boyfriend" is from the Ramones' first album "Ramones" (1976). Had Tom actually been listening to their newest album, he would have been listening to "Road to Ruin" (1978)...which does not include the song "I Wanna Be Your Boyfriend".
When Angel Dust and Riff Randell are continuing to argue about who's in line first, the Ramones pull up. They begin to push and shove each other. Angel's hair starts being pulled up, neatly. As her and Riff push to get the Ramone's attention, Angel's hair falls down. But after the Ramones are done singing, their manager approaches Angel, and her hair is up neatly once again.
When Dee Dee yells "Hey pizza! Dig in!" the pizza boxes aren't open yet but in the previous shot with Joey in the foreground, the boxes are already open and the rest of the band are already taking out some slices.
Backstage at the Ramones concert, after Kate finds Tom sprawled out on the floor, while the two of them are talking the shower curtain dress she's wearing comes off her without her making any apparent effort to remove it.
The seniors at Vince Lombardi High School wear class buttons which read "1980." The freshman who is the continual victim of upperclassman abuse wears a class button that reads "1984." Freshmen of that year would have been from the class of 1983, not 1984.
During filming of the concert scenes, the camera focused on P.J. Soles and Dey Young ran at the wrong speed, giving the footage a very speeded-up look. The filmmakers added the scenes into the picture anyway.