Continuity mistake: In this episode Randy is allergic to cats, in fact he has an allergic reaction even if a cat has been there lately but is not there now. But in Mr. Monk and the Sleeping Suspect, during the scene where Monk and the police are investigating the woman's destroyed house, a cat passes within a few feet of Randy, who doesn't sneeze or show any signs of his allergy.
Continuity mistake: Monk identifies the kidnappers' house by the pizza box outside by the bin. In the wide shot it's upside down on its corner, with "zza" just visible behind a black bag. In the closeup it's turned around, so we can see more letters, and it's moved.