Step By Step (1991) - 8 mistakes in entire show

Continuity: In this episode, Steve Urkel appears, depicted as a real person. But Urkel also appeared in a few episodes of Full House, which, within the universe of Step by Step, is a fictional television series.

Visible crew/equipment: When they are taping the family, Carol gets mad and goes upstairs and the camera guy taping her tapes her going up the stairs and when he does, for a second, you can see where the set ends and all the lights.

Revealing: When the band is playing the show at the end, JT is supposed to be playing the bass, but anyone can tell he is not, even when the bass sound is used.

Continuity: At the end of the episode, Frank is talking to his mother in the kitchen, and she sits down at the table. The green jacket on the chair behind her keeps changing positions between shots.

Factual error: Carol and Frank leave for a romantic weekend and Dana begins to tutor Rich for a test in English Literature. When Frank and Carol return on Sunday Rich has not only studied for the test but also TAKEN the test and gotten the results back. How is that possible over a weekend?

Other: When Black Bart repeats his line about how sheriff Frank is a washed up, yellow bellied, gin guzzling pile of buffalo chips his French accent is gone and the actor's real American accent is heard.

Deliberate "mistake": When Frank tosses the cards in the end they all hit the camera very obviously. When the episode first aired the last scene was in 3D, which is why he tosses them directly at the camera like that.

Plot hole: Jean-Luc has been around the entire season, yet now he shows up and nobody knows who he is?