Continuity mistake: When Marty bangs open the crane's cage, he is about a foot away from where he had been in the previous shot, when the crane pecked him on the rear end. To achieve the latter he had to be fairly close to the bird, but to accidentally open the cage easily by pushing at it with his cane, he had to be standing farther away, or it wouldn't have worked. He moves that distance from shot to shot and it just wouldn't have happened in real time.
Continuity mistake: After Frasier is left alone in the apartment, we can see a glass of sherry and a can of beer on the coffee table, but neither item was on the table when he was talking to the others before they left the apartment. Roz's purse also shifted from the couch to the little glass table during the shot change. (00:21:20)
Continuity mistake: Roz has just received a call about Marty's missing chair and as Frasier comes into her booth, she is writing it down. As she says "I found the chair", she hands him the paper - but she goes from writing to handing it to him with no time in between. (00:16:35)
Continuity mistake: At the end of the show Frasier, Niles and their dad are having drinks and Niles goes to top off Marty's shot glass - but just as he pours the drink, Martin pulls it away. In real life the drink would have ended up on the floor, but the scene continues as Niles keeps pouring into the glass.
Continuity mistake: At the hospital the nurse comes over to talk to Frasier about his father - her paper on her clipboard is flipped over the back of it and her hand is holding the side of it. A couple of shots later, with no opportunity to change positions, the paper is no longer flipped over and her hand is lying on top of the clipboard.
Continuity mistake: Towards the end of the show, Daphne, Niles, Sherry, and Martin are in Frasier's bathroom where he is trying to take a bath. He starts talking to Sherry - she is sitting on the ledge at the end of the tub. From one shot to the next she has her left leg crossed over her right, then her right over her left, and then both legs uncrossed. She did not have time to shift her position and there is no "residual movement" that would have been natural had she been fidgeting while he talked to her.
Continuity mistake: When Bulldog is talking to Frasier in the booth at KACL, in one shot his left sleeve is pushed up his arm and his right sleeve is down to his wrist. In the next shot it's just the opposite - his right is pushed up and the left is down. At the end of the scene both sleeves are pulled up.
Continuity mistake: While Marty and Frasier are fighting Marty smashes some plates. The shot changes to the living room with Frasier apologizing and then switches back again. However, now all the smashed crockery has disappeared to be replaced by what looks to be a bowl and a tumbler.
Continuity mistake: Frasier is based on the character originally created on Cheers. In Fraiser, he lives with his father who is a retired police man. On Cheers, Frasier once mentioned his father was a scientist. It's also worth noting that in one episode of Cheers, John Mahoney, who was to later play Frasier's dad, turns up as a pianist. Frasier also said on Cheers that his father was dead. When Ted Danson made a guest appearance on Frasier, Frasier admitted that he had lied about his father since the two had been arguing so much.Jack's Revenge
Continuity mistake: When Niles and Daphne are on the couch talking about the meteor shower, she has his hand on his left knee and he is covering it with both of his hands. After he says "two horrible wrongs", his right hand is suddenly on his right knee, with no time for natural switch.
Continuity mistake: Eddie has been playing on Niles' couch, and the pillows are all over the place and there are a couple of other things on there as well. After Marty's chair arrives, Niles says to Frasier, "You have to take him back now," and suddenly the couch is all tidied up, with the pillows at the ends. A couple of shots go by and suddenly the couch is a mess again.