The little plastic shovel in Niles' hand changes color from yellow to blue and back to yellow between shots.
After Daphne's (Jane Leeves) friends leave, Martin (John Mahoney) and Daphne go into the kitchen. One second the jersey is undone, and the next second all the buttons are done up.
When Niles is talking to Frasier in the coffee shop, Niles' coffee cup either has its lid on or off depending on the camera angle.
During exterior shots of the beach house the top edge of the evening sky set
backdrop can be clearly seen.
When Daphne (Jane Leeves) leaves, she says to Martin (John Mahoney) (in part), "Mistake my fanny..." In England (and Australia) the word "fanny" is not synonymous with "rear end"; it refers to the female genitalia, and thus makes it a less likely thing for Daphne to say.