Other mistake: In the kitchen, when Niles burns his hand you can see him move his hand down to stop the frying pan from falling off the stove. He doesn't touch it again, but it looks like the instinctive actions of someone who knocked something over rather than part of the scene. He just slips out of character for a moment.
Continuity mistake: When Frasier is offering to help Lorna carry her books, her purse switches from her right shoulder to her left arm and back to the right from shot to shot.
Answer: In the last episode, they explained that Tossed Salad and Scrambled Eggs is a metaphor for the mixed-up people to whom Frasier dispenses his radio psychiatric advice.