Continuity mistake: In the restaurant, Frasier and Ann are at Kenny's table - Kenny puts his napkin down and leaves the table, while Frasier puts his cellphone away. In the next shot, the napkin has changed position on the table and Frasier is putting his cellphone away again.
Continuity mistake: Frasier puts the tuna on the coffee table for Mr. Bottomsley and the cat jumps up and starts to eat it - he is facing the couch. In the next shot we see Eddie come into the room and suddenly the cat has moved and is facing Marty's chair - without enough time for the change.
Continuity mistake: During the opening credits of the show, Frasier and Roz are in Cafe Nervosa. Frasier has a fabric shopping bag, and in some shots you can see the leaves of one vegetable and in other shots you can see the leaves of two vegetables. These leaves are quite large and distinctively different.