Continuity mistake: In the doctors office, the doctor wheels Ann out and leaves the X-Ray he just put up of her leg. Later in the scene after Martin and Frasier have their conversation, Ann comes back into the room on crutches. When she does, the X-ray that was on the board has disappeared and never returns through the rest of the scene.
Continuity mistake: While Ann is talking to Frasier near the door of his apartment, his coat is over the arm of the couch. After Frasier closes the door after Caroline's brief visit, the coat is over the back of the couch, even though no one went near it during that time.
Continuity mistake: Maris is hiding in a wooden box so she will be shipped out of the country. Marta, her housekeeper, has a protein shake for her, and puts the straw through a hole in the box. Maris indicates that she's drunk too much and Marta goes to put the straw back in the hole so she can regurgitate some - but just before that happens we see a stream of the liquid come out of the hole and dribble down the box. In the next shot the straw goes into the hole and the box is all clean and dry again.