Traylor Howard (Natalie) really was pregnant during production. Thus, in every scene in which she appears, her stomach is concealed behind something, whether it be a car, a table, or a coat. The only exception is when Natalie "pretends" to be pregnant; then her stomach becomes completely visible.
When Monk assesses the laid-out silverware on the table, he finds a fork "one centimeter too close." When Mrs Murphy, head of housekeeping, says "it's only a centimeter," Monk corrects her with "For want of a nail, the kingdom was lost" referring to the proverbial rhyme:
For want of a nail, the shoe was lost.
For want of a shoe, the horse was lost.
For want of a horse, the rider was lost.
For want of a rider, the message was lost.
For want of a message, the battle was lost.
For want of a battle, the kingdom was lost.
And all for the want of a horseshoe nail.
The jigsaw puzzle Monk solves while waiting for Paul Buchanan (Sean Astin);is a photo of the Miami skyline.
Ashley Johnson, who plays Susie the maid, was a child actress who appeared on Tony Shalhoub's other series Wings (1990).
When Monk is arguing with a guest about taking the duck over the quail, there are two empty seats to Monk's left, one for Natalie and one for the host, Paul Buchanan. When the camera angle changes, Paul Buchanan is sitting in his seat.