In the book store, Frasier (Kelsey Grammer) asks Roz (Peri Gilpin) to buy the book. Roz never leaves to buy it, and ends up leaving the store without paying.
When Frasier tells Honey he finds her chapter titles "jejune," she replies that he uses too much French in everyday conversation. Jejune is actually a Latin word, not French. (Since Honey isn't a learned wordsmith, however, it's probable that she didn't know this.)
'Ride of the Valkyries' is supposed to be performed by eight sopranos, not one.
Roz shoplifts the book from the book store. Frasier and her says they were going to pay for it..but Roz walks out with it.
In the last conversation between Niles and Frasier, David Hyde Pierce is trying not to smile.
When the title card "Are there any more like you at the institute?" is shown, the executive producers graphic appears for a split second, faintly. When the title card "Shrink Rap" appears, you can see very faintly below "Guest Starring Paul Johanasson."
Martin didn't stand up when Dr. Snow entered the room. Even with a slight disability, a man of his generation would show respect for a woman by rising.