Continuity mistake: When Will enters Barry's apartment with the big brown bag of Chinese food, he walks over to the chair and puts it down. On the table is a magazine laying parallel to a book. A shot later the magazine sits vertically to the book.Hamster
Continuity mistake: In the episode "Grace, Replaced", with the neighbor Val who moves into "apartment 15F" in the same building as Will and Grace. Yet in the previous episode "Yours, Mine or Ours" with Peter (who moved into 12D) we learn that 12 is the highest floor in the building...Hamster
Continuity mistake: When Jack is trying to hush the audience at his show Jack-Talk after bringing Grace onto the show for a follow-up interview, between shots the little bell on his desk moves from his right (near the edge) to over past his left, near the centre of the desk with all the other items. (00:15:55)Hamster
Continuity mistake: When Grace is setting up her design class, she writes "Professor" on the board, and curls the end of the R into a spiral. But in the shot when she says "T.A. - Teachers Assistant" the spiralled end on the R has gone. In the next shot it's back again. (01:04:40)Hamster
Continuity mistake: In this episode, Karen doesn't want to get glasses because she thinks they make her look old. However, in a previous episode (S1E9) we see that she actually already wears glasses. In a scene where Jack asks her to read his script, she quickly puts on a pair of reading glasses.
Continuity mistake: Shortly after arriving at their mother's house, Will's brother, Sam, nervously excuses himself from a conversation with Grace. "Excuse me," he says, "I have to go get a ladder. There's a couple of bulbs out in front, and now it just says 'Happy Ho-days.'" However, exterior shots of the front of the house show no holiday lights whatsoever.Michael Albert
Plot hole: Jack spends part of this episode clumsily teaching Karen basic steps of the fox trot for her wedding dance with Finster. However, in season 4, episode 16 ("A Chorus Lie") It is established that Karen and her husband Stan have, for years, performed an annual spotlight dance at their Valentine's party on Shelter Island. Later, she and Will are seen beginning a rather elegant fox trot to "Someone to Watch Over Me," complete with spins and a dip.Michael Albert
Character mistake: When talking to Will on the phone, Grace misuses the term "pied-à-terre" (which means "apartment" in French) instead of "pas de deux" (a dance for two) while describing the delicate and complex nature of a relationship between two gay men. When Will points out her error, she says she knows what pied-à-terre means because she took Spanish in high school. However, in season 1, episode 20 ("Saving Grace"), Grace correctly and easily used the term pied-à-terre while showing her sample book to a potential client.Michael Albert