The Busboy - S2-E12
Continuity mistake: At the end of the episode Elaine, George, and Jerry are sitting in the coffee shop and the ketchup moves from inside by Jerry to the outside of the table when Elaine's to-go order is put on the table.
Seinfeld (1990)
1 continuity mistake in The Busboy - chronological order
Starring: Jason Alexander, Julia Louis-Dreyfus, Michael Richards, Jerry Seinfeld
Genres: Comedy
Character mistake: When George and Elaine go to the coffee shop after The Movie without Jerry, they establish that Elaine moved to NYC in 1986. Then they make fun of the way that Jerry throws up; both imitating Jerry. The "Dinner Party" episode is after the "The Dog". In the "Dinner Party" episode, Jerry brags that he hasn't thrown up since June 29th, 1980. The black and white cookie ended this streak. Elaine would not have been around to see this, not arriving in NYC until 1986.
More quotes from Seinfeld
The Robbery - S1-E2
Trivia: Michael Richards invented his patented Kramer entrance in this episode on accident. He missed his cue and thought he would make up for lost time.
The Suicide - S3-E15
Question: When George and Elaine go to see the psychic, the psychic tells George that she sees a Pauline. George gasps and says that his brother once impregnated a woman named Pauline. Since when does George have a brother? Was this brother shown or mentioned in any other episode?
Chosen answer: George does mention his brother in the episode "The Parking Space". They actually really never mention anything that contradicts the fact he had a brother though, it just isn't mentioned.