Continuity mistake: As Kirby is showing Roz his prom pictures, she sees the picture with his hand on her behind. In the scene her hair on her right changes position in the following shots from on her chest, to slightly behind her shoulder, to completely behind her shoulder.
Continuity mistake: Frasier and Niles are looking at the salt server Blaine returned to Frasier - in one shot the large envelope, the mailer strip, and the note are on the coffee table - in the next shot the strip has disappeared and the envelope and note have changed position.
Continuity mistake: When we first see Marty on the floor oiling his chair, his cane is lying on the floor with the handle end pointing towards the kitchen. When he picks it up a few shots later, it has turned 180 degrees and the handle is pointing towards the door. At no time did he touch it.
Factual error: Simon, having just been kicked out of Frasier's apartment, is trying to convince Roz to let him stay at hers. In the background the set shows a wharf area with at least one tall ship, Alito's Restaurant, Pier 45 Shed A, and Fisherman's Grotto. These are all located at Fisherman's Wharf in San Francisco, not Seattle.
Continuity mistake: Martin says that Eddie will find the cricket, and puts him down on the floor so he can begin to search. He places him right in front of the green chair. In the next shot, we see Eddie spinning around on the floor, but the chair isn't visible in the frame like it should be. Instead there's something that looks like a gray stool there.