After Linda signs off, Stottlemeyer mentions that she and Sean Corcoran had been together for 17 years, to which Natalie replies that, "that's longer than most marriages." Stottlemeyer replies, "Longer than mine." Yet, it was established in Mr. Monk and the Captain's Marriage (2006)(#4.12) that he was married to Karen for 20 years.
When Stottlemeyer is interrogating the female suspect, he intentionally pulls the blind so it's slanted to upset Mr. Monk. The angle of the blind changes from steep to less steep and back.
When Monk examines the closet in Linda Fusco's house, he sniffs on the barrel cleaner for the shotgun. This cleaning brush is straight first and bent a few seconds later.
When Stottlemeyer is "torturing" Monk during the interview, he breaks off the first piece of styrofoam cup and drops it, the next wide scene shows two pieces of cup on the ground.
At the end, when Randy and Stottlemeyer are on the beach, a frontal shot shows Randy's towel draped over his chair, with the top of the cushion visible. In following close-up and rear shots, the towel is tucked in, covering the top of the cushion.
The bore brush on the cleaning rod that Monk finds in Linda's closet is not for a shotgun; it is actually for a rifle, probably a .22 caliber.
When Adrian Monk is looking at Linda Salvato's rental receipt, it shows a ZIP Code (postal code) of 94677. There is no such ZIP Code in America.
Early on the investigation is depicted as being handled by police in Marin where the crime scene is located with Lt. Hendrix as lead detective. But this angle is quickly dropped, most prominently by having Leland interview a lead suspect and later confess to Linda that the San Francisco Police have reached a dead end to solving the case as if the murder happened in SFPD's jurisdiction.
When Mr. Monk is waiting for Natalie in front of the house, his head rapidly shakes from side to side for a second as if there's a problem with the film.
In the opening scene (chainsaw) when Leland surprises Linda in her front yard, something (possibly a body microphone) under her robe (in the back) drops to the ground and it is audible. But, it is never explained. It is not her cell phone which she is holding in her right hand.
When Monk and Natalie are riding the motorcycle in what is supposed to be northern San Francisco, a Los Angeles street sign for Dodger Stadium is in the background.
When everyone walks out to the parking lot to look at the rental truck, there is a steep, tall hill visible very nearby in the background. There are no hills like this in the city of San Francisco, where the scene was set. There are however, hills just like this nearby the Hollywood/Burbank area where the series is filmed.
When Monk asks Linda if she reported the shotgun stolen, she replies "Yes, it would be a crime not to." Although several attempts have been made to make it a crime not to report a stolen firearm in California, there is no law that requires this. The exception is if you are an FFL (Federal Firearms License) holder. They must report stolen firearms within 48 hours, but a private citizen has no such requirement.