Mr. Monk and the Rapper - S6-E2
Continuity mistake: After Monk tries to get out of the contract with Murderuss, he walks to Stottlemeyer with jewel necklaces around his neck. In the next shot (after Stottlemeyer asks "How did that happen?"), the necklaces have disappeared. (The golden teeth stay, though).
Mr. Monk and the Rapper - S6-E2
Continuity mistake: When Murderuss introduces Snake, we see Monk turn to shake his hand and the briefcase on the table is closed. But in the next shot, it's opened.
Answer: The two men are trying to work out a secret deal between them without involving the union, which means the workers' interests aren't being represented and defeats the whole purpose of a union. The mayor would lose labor's support and Cusack's union troubles would just be starting.
Captain Defenestrator