Continuity mistake: The age gap between Eric and Cory decreases as the series progresses. At the start of the show, Cory is in 6th grade and Eric is a high school sophomore, meaning they are four years apart, give or take a few months. By season 3, Cory is in 9th grade (confirmed by dialogue mentioning that Shawn, who is in the same grade as Cory, is 15 years old), and Eric is a senior, leading to an age gap of three years. The first episode of season 4 takes place a couple months after the end of season 3, with Eric and Cory returning from a summer Road Trip, but just two episodes later, Cory mentions that he is in 11th grade, while Eric is still barely out of high school, leading to an age gap of two years.
Plot hole: At the beginning of the episode, Eric and Jack call the cops on Luther for planning an illegal rave at the college, but the cops let him go because he had not started the rave. He still broke into the student union building, and therefore should have still been arrested. He even threatens Eric and Jack afterwards right in front of the cops, and they do nothing about it. (00:00:20 - 00:02:10)
Character mistake: At one point Cory is telling Shawn about how he can't protect Topanga and they've only been married for one week. But they spent their wedding night in jail, 12 days on their honeymoon and 1 night in their new apartment. So actually the couple have been married for 2 weeks.
Continuity mistake: At the end of this episode, you see Griff standing with Joey and Frankie. He's wearing a jacket over a pink button down shirt that has a red collar and red accents. He sees a girl, and the camera moves to Joey who stands up on the bench and screams at the girl, then when the camera goes back to Grif, he's wearing a jacket over a plain old faded red shirt. I wonder what happened to the other shirt.
Factual error: Throughout the series we are told over and over that Cory and Shawn have known each other forever. We see the boys and Topanga meet when they are about 6 years old, and Cory says at one point that Mr. Feeny has always been their teacher. But in this episode Mr. Feeny says Shawn was born in Ohio, lived in Oklahoma and was in and out of 5 schools by the age of 12. This implies that the boys did not meet until middle school, (age 12, when Shawn arrived in PA).