Continuity mistake: When Natalie props the get-well card up on Monk's bureau, it's partially open. The moment the shot cuts to a different angle, it's completely closed. (00:10:15)
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)
Continuity mistake: After DeLancy loosens the tie Stottlemeyer gave him, the position of the knot changes without him touching it.
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