Lassiter says "she's as guilty as Mrs. O'Leary's cow," a popular phrase referring to the widely-circulated theory that an accident involving Irish immigrant Catherine O'Leary's cow inadvertently caused the Great Chicago Fire of 1871. It was later determined that neither O'Leary nor the cow were to blame, and the cow was in fact posthumously cleared of any wrongdoing by the city council of Chicago.
Shawn introduces himself to the masseuse by saying, "I'm psychic detective Shawn Spencer. That's my brother Darryl, and my other brother Darryl." This is a reference to the series Newhart (1982), in which three brothers often introduce themselves in a similar manner, "Hi, I'm Larry. This is my brother Darryl, and that's my other brother Darryl".
The building purported to be the exterior of the Diamond Surgery Group's offices is actually the police station in Glendale, California, at 131 North Isabel Street.
The character of Brad Turner is named after one of the show's directors.
In the couples massage scene, Shawn and Gus go by the aliases of Mr. and Mrs. Nusbaum. This is a reference to The Jerk (1979) staring Steve Martin. In the movie his character, Navin Johnson, catches the guys who stole Mrs. Nusbuam's credit card.