When the Ambassador's body is shown in the elevator, he is wearing his coat, but only about five seconds elapsed between the last shot being fired and Steven Leight shown running away. There's no way he would have had enough time to remove his own coat from a dead body and put the other one on, then position the body the way it was sitting in the elevator.
When Monk is examining the crime scene in the NYC hotel, Capt. Stottlemeyer and Lt. Disher walk under the crime scene tape to talk with Monk. Stottlemeyer continues on unimpeded, but Disher is stopped from continuing by a NYC cop. The camera shifts back to Monk and Stottlemeyer is walking towards him, but Disher is stopped again by the same cop after crossing the crime scene tape.
Captain Walter Cage is seen wearing an NYPD detective's badge. An NYPD captain's badge has no badge number and is a different shape with 5 points on top.
Obviously, San Francisco police officers would have no jurisdiction in New York City.
When Mr. Monk and Sharona are interviewing Mr. Gratnik, he loses the chess game to a mate by the White Queen. While this is a solid checkmate, it could not have happened. Before the Queen moved to the Black Queen's 2 square, the Black King was already in check by the White Bishop in the Queen's Bishop 3 square.
Additionally, as the Queen always starts on its own color, the position of the Kings seems to indicate that White is playing Black squares while Black is playing red squares.
Additionally, as the Queen always starts on its own color, the position of the Kings seems to indicate that White is playing Black squares while Black is playing red squares.
Monk refers to a .22 as a peashooter. Despite its size, the .22 has one of the highest one shot stop rates of any caliber.
The front of an A train is shown, but subway cars they exit are of a C train.
When the Ambassador is shown lying dead in the elevator immediately after his assassination, you can see the actor breathing.
The NYPD office is the same set used for the SFPD office. It's easily noticed by the distinctive windows.
When Monk falls onto the ice in the ice rink, his wireless microphone transmitter box falls out of his pocket and can clearly be seen sliding along the ice beside him.
After Captain Stottlemeyer gets off the phone with Captain Walter Cage at the cafe, he incorrectly refers to him as Detective Cage.