Continuity mistake: When Daphne and Niles are on the roof having their picnic, the basket behind them is opened from the center and on the inside on the left are two champagne glasses. A couple of shots later and the glasses are now on the right side, even though no one touched the basket.
Continuity mistake: Frasier is in Donny's office, and Donny is holding a little wedding cake groom. He covers the groom with his hands while he's talking, but when Frasier says, "Daphne realizes you went to great expense," the little bridegroom is visible again, even though in real time it couldn't have happened.
Continuity mistake: At his "reception" Niles has his arm around Mel and says, "I didn't even have to check her teeth" to a member of the horsey set - and the shot then shows Mel and Nils standing apart, even though there was no time for them to have done this.
Continuity mistake: After Roz has had the baby and has fallen asleep, the nurse comes in and watches Frasier kiss her on the forehead. Most of the time she is standing at the door with her hands behind her back, but in one shot her hands are in front of her and she is holding something white. When she flounces out after Frasier hits on her, she has nothing in her hands.
Continuity mistake: Daphne gives Marty a brightly coloured sweater for Christmas and after he opens it, he puts it back in the box - the yellow sleeve is hanging out. After he says "all that makeup on my face", the sweater has changed position and there is a red portion hanging out of the box. No one touched it in the meantime.