Mr. Monk and the Really, Really Dead Guy - S5-E15
Factual error: The FBI agent runs a computer check and prints out a list of all the pet stores in San Francisco selling ferrets. But he shouldn't have been able to generate any list at all. Pet ferrets are illegal in the state of California, and are not sold in pet stores there. (00:15:00)
Mr. Monk and the Really, Really Dead Guy - S5-E15
Continuity mistake: In the scene where Monk mistakes the plasma TV for a blackboard, he writes the words "BODY MOVED" on the screen. Initially, he writes the "B" with an extra long vertical stroke; the next time we see the text, the vertical stroke is of a normal length. The text reads "BODY MOVED" when Monk stops writing, but when the FBI agent walks over to the screen to try to wipe it off, it has changed to "BODY M".
Mr. Monk and the Really, Really Dead Guy - S5-E15
Factual error: In real life, the FBI does not have jurisdiction over routine homicide cases, which are almost always left to the local police. They have no jurisdiction over serial murder at all, unless a federal employee is a victim or one of the murders gets committed on federal property (like an army base, federal prison or national park, or on sovereign territory like a reservation). The only time the FBI would be involved in a homicide is if the individual crossed state lines in committing the crime.
Mr. Monk and the Really, Really Dead Guy - S5-E15
Visible crew/equipment: Inside the CSI van, when the investigators all turn to look at Randy, an equipment shadow sweeps across the wall at the upper right of the screen.
Mr. Monk and the Really, Really Dead Guy - S5-E15
Factual error: Monk typing the address into his laptop would not affect the trace the agents are doing, it definitely wouldn't pop up on the agent's screen as the result of the trace.
Mr. Monk and the Really, Really Dead Guy - S5-E15
Plot hole: In this episode, Monk doesn't know to open a cell phone to answer it, but in "Mr. Monk and the Kid", he used a cell phone with the ransom drop with no problems. (00:04:25 - 00:05:05)
Answer: Notice also that in the opening credits scene when he is touching parking meters her also wipes his hand on his clothes each time he does it.