Right before the part where Kristy Masters announces to the reunion that Romy and Michelle claimed to have invented post-it's...She's going through a list of accomplishments of other graduates of Sagebrush High School. They show a clip of Heather (Janeane Garafolo) with some sputtered beer on her dress. It shouldn't be there during that first shot, because it's not until the next one of her (when Kristy announces the name of the guy who is with the Dallas Cowboys) when she actually sputters the beer, mocking him.