Mr. Monk and the Candidate (2) - S1-E2
Other mistake: When Monk is climbing the ladder to pursue the killer, at a couple of points, he wipes a rung, then grabs the one above it. (00:18:15)
Mr. Monk Goes to the Carnival - S1-E5
Other mistake: Kitty, the killer, is seen running to Gitomer after Lt. Kirk leaves him. She is supposedly running to stab him, but you can see that both of her hands are empty as she dashes to his side.
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