Continuity mistake: Niles and Frasier have drugged the rottweilers with some of Maris' pills and Frasier points towards the french doors and says, "The dogs are getting drowsy." We see the dogs dropping to the ground. The next shot of the doors, a couple of seconds later, shows no sign of the dogs, although they were visible from that angle just before that.
Continuity mistake: At the beginning of the show, Niles and Frasier are in Cafe Nervosa. As Niles says "Matthew Pimm tried to stage a coup", we can see Frasier's hand on his napkin next to his mug. As the shot changes, suddenly both of Frasier's hands are on his mug.
Continuity mistake: Frasier is hiding behind the kitchen counter when Ronee comes in - followed by Marty. Frasier puts his hands, one holding an apple, up on the counter. In the next shot the apple is on the counter, and his hands are draped over each other - without enough time for natural movement.
Continuity mistake: When Niles and Kit are at Frasier's apartment, Kit does a quick dance with her arms out and tells them Niles is taking her to Euro Disney. A couple of shots later her little purse is back under her arm, even though she had no time to pick it up from the bookcase.
Continuity mistake: Frederick appears in the kitchen to talk to his parents, who are ignoring him. In one shot he is covered with spots and in the next, he only has about half as many. He is supposed to have hives, which I know can appear and disappear quickly, but these look nothing like hives in the first place.
Continuity mistake: When Frasier and Kate are in the airport, sitting down and talking, her arms switch back and forth from being folded to unfolded (holding her boarding pass). This happens a couple of times, without time for her to change position.
Continuity mistake: There are several bad cuts between shots when Niles and Frasier are on the balcony. Keep an eye on the height of Niles' sherry glass. The most noticeable occurrence is when Niles mentions "detachment" and the shot changes. He is suddenly holding his glass at least a foot higher in the air.David Mercier
Continuity mistake: When Frasier, Marty, and Niles are having drinks at the end of the show, Frasier says "I think we have a 3-way tie" and we see Marty holding his drink in his left hand - the shot then switches and it's suddenly in his right hand, with no time for a natural change.
Continuity mistake: When Frasier is in the boardroom with Roz and her production team, Frasier is writing in a binder, which is on top of a couple of books. In some shots we see a couple of different books in front of him on the table. One of them is called "Mars," which he had put back in his briefcase at the beginning of the scene.
Continuity mistake: When Daphne is playing darts with Frasier, he says, "I scored again," and we see her sweater sleeve is pushed up her arm. But when she comes back with, "That's not something we hear very often," the sleeve is completely covering her arm. In the next shot, it's pushed up her arm again. There was no time for the adjustment.