Continuity mistake: When Frasier and Martin are leaving Artie's hospital room, Frasier has the door about one-third open. Just before they leave, though, as Frasier says "next time he'll stay longer", the door is open much wider. Nobody opened it wider during that time. (00:08:50)
Continuity mistake: Martin is drinking a glass of milk which is between his arm and a bowl of chips. Suddenly the milk is sitting well to the left, even though he didn't touch it. (00:14:35)
Continuity mistake: Marty is sitting at the dining room table and for a couple of shots he's eating potato chips with his right hand; the shot changes to him eating with the other hand, with no time for a natural shift. (00:14:50)
Continuity mistake: When Daphne and Martin are sitting at the dining table talking about Arty, Martin has a bowl of chips and a glass of milk which change position between shots.
Continuity mistake: During the scene where Martin is apologizing to Artie in the hospital room, the photo of Artie's wife on the bedside table changes position about 45 degrees while they talk.
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.