Plot hole: When Stottlemeyer and the other cops arrive at the recycling center, the patrol car's siren turns on and off. The killer had said to Monk that if he called the cops, he'd kill Natalie. Coming to a hostage situation with the siren going would be a really bad idea. (00:37:45)
Continuity mistake: When Monk is trying to join the two cops' conversation about football, in the shots from the side of the police car that they're standing near, the two cops are standing less than a foot apart. In the shots from the other side of the car, they're far apart enough for Monk, Natalie, and Captain Stottlemeyer to stand between them. (00:03:00 - 00:05:00)
Continuity mistake: When Monk and Natalie are talking to Kemp in his office, the desk ornament and the cup of pencils that Monk keeps organizing change positions between shots. In the shots from Monk's side of the desk, the ornament is closer to the door. In the shots from Kemp's side, the pencil cup is closer. (00:09:40 - 00:11:20)
Continuity mistake: When Natalie and Al are struggling, the gun lands on the table and there's a basket of corks. Somehow when Al gets the gun, the basket is tipped over and the corks are on the table. But after Monk hits Al, the corks are all back in the basket, which is upright.
Continuity mistake: When Monk and Al are sitting to drink wine, Al grabs his bottle with one hand to pour the wine and the other hand is hanging down to his side. In the next shot, as he's pouring the wine, he's holding the glass with the other hand. In the next shot, his hand is by his side again.
Factual error: In the flashback where Monk is explaining how the money was stolen, the principal finds the 5 dollar bill he wrote "good luck" on and holds it up for everyone to see. The bill he holds is a 5 dollar bill which was released in 2000, with the enlarged Lincoln. The flashback takes place in 1972.
Factual error: When Monk is talking to Sherry about the painting in the art gallery where the painted woman was going to kill her husband, he says that she has a bruise on her left eye. But the bruise is actually on her right eye. While it is viewable that it is on Monk's left, he would not make that mistake.