Continuity mistake: Frasier is having a glass of sherry, sitting on his couch, talking to Niles and Martin. As Marty says "let's go have dinner", Frasier throws his hands up - in real life he would have still had the sherry in his hands. There was no time for him to have put it down.
You Can Never Go Home Again - S3-E24
Continuity mistake: Roz has a cassette in her hand as Frasier says "call-screening squelches all that," - and the next shot shows no cassette in her hand, without time for her to get rid of it.
Moon Dance - S3-E13
Continuity mistake: Early on in the show, Martin is trying to get Eddie to shake a towel off his head while Daphne stands behind the dog, folding laundry. In one shot she is standing with the folded towel over her arm; in the next shot she is folding it again. When she goes to the door, there is something red on top of the laundry basket, but when she returns the towel is back in the laundry basket (it's not the towel Marty put on Eddie's head: that's sitting on the coffee table).
Continuity mistake: When Manu pulls down the metal front over his kiosk, Frasier has his umbrella in his right hand. By the time Manu pulls it all the way down and catches his hand under it, Frasier's umbrella has shifted to his left hand, even though he never transferred it.
A Word to the Wiseguy - S3-E15
Character mistake: In the scene where Jerome Belasco turns up unannounced at Frasier's apartment, Daphne tells him she's psychic and guesses that he's an osteopath. After Jerome leaves, Daphne says she thought he seemed very nice. Frasier turns to her and says, "This from the psychic who said he was a chiropractor."
Visible crew/equipment: A boom mic is briefly visible when Frasier is talking with Kate in the hall. (00:11:09)
Revealing mistake: Frasier, Roz and Ben are sitting at a table in Cafe Nervosa. However, as the camera is panning out when Ben sits down you can see the outside of Cafe Nervosa because the wall is only a small partition. The camera zoomed out too far. (00:06:30)
You Can Never Go Home Again - S3-E24
Continuity mistake: When Frasier turns up to the office on his first day, having never met Roz before, he has the briefcase that Roz got for him as mentioned by Roz and Niles 'Fool Me Once, Shame on You, Fool Me Twice...'. How can this be if they've never met before?
The Friend - S3-E11
Continuity mistake: While leaving Nervosa, Bob has the BBQ book in his lap. After Frasier leaves, the book is back on the table. (00:12:10)
Continuity mistake: The shot after Roz says "Roz Doyle, radio producer, single" shows the guy nearest to the window in the other room with his left hand next to his mouth and the woman next to him with her hand next to her chin. The following shot shows the man closest to the window with both his hands next to his mouth and the woman sitting next to him with her hands on her lap. (00:07:35)
Where There's Smoke There's Fired - S3-E21
Continuity mistake: When everyone is sitting at the table having dinner, the amount of food on Bebe's plate changes repeatedly. She adds extra food twice, once from the pot and once from Martin's plate, but the difference in portion sizes changes more times than that and without time for it to be eaten. (00:11:05)
The Last Time I Saw Maris - S3-E8
Continuity mistake: Daphne is holding a fire poker when she is having a psychic message. Just after Niles says "Oh dear God", the poker is held straight up. In the next shot, the poker is partially lowered. (00:03:35)
Answer: It equals the record of James Arness of "Gunsmoke" for the actor who's played the same part on TV NOT in a soap opera. If you include soaps there are two main contenders - William Roache, who's been playing Ken Barlow in "Coronation Street" in the UK since 1960. Don Hastings has been playing Robert Hughes in US soap "As the World Turns" since 1960 as well.