Other mistake: During the flashback of the perpetrator beating up the victim with a baseball bat, the shot is visibly spliced and there's a jump cut while he is between swings of the bat. (00:32:50)
Mr. Monk Bumps His Head - S4-E11
Other mistake: The diner Monk enters to eat something after the truck driver gave him five bucks is the same diner that Christie and Sharona are waiting in to meet Monk after work in the episode Monk and the employee of the month. But while this episode is said to be in Wymington, the earlier one is set in San Francisco.
Suggested correction: This is trivia at best. While the set may be reused, it's not meant to be the same diner. It might be a chain restaurant so they look similar, but the seats inside are different.
Mr. Monk and Little Monk - S4-E8
Other mistake: The camera, although it is supposed to be stationary, is visibly shaking during the shot of Monk and the woman discussing the painting. (00:23:45)