Other mistake: This is for the episode "Crock Tales" (the 22nd of the season). Almost all the flashback sequences are wrong in time. The one from 2003 has Niles and Daphne coming back from their honeymoon but they married in 2002. Although not ever couple take their honeymoon directly after they've married, the wedding episode "Ring Cycle" mentions them going on their honeymoon.
Frasier (1993)
1 other mistake in season 11 - chronological order
Starring: Kelsey Grammer, David Hyde Pierce, John Mahoney, Jane Leeves, Peri Gilpin
Visible crew/equipment: When Frasier is standing through his sunroof to speak with the drivers stuck behind him in the parking garage, one shot shows Frasier's body and much of the rear window which features a very clear reflection of the boom mic.
More quotes from Frasier
Trivia: When Nanette tells Frasier she's tired of playing her children's show character, she asks him if he knows what it's like to play the same character for twenty years. By this point, Kelsey Grammer had been playing Frasier for twenty years: eleven on 'Frasier' and nine on 'Cheers'.
More questions & answers from Frasier
Chosen answer: The turkey's stuffing.