Mr. Monk and the Airplane - S1-E13
Stupidity: When the pilot asks Monk for some ID, who cannot provide it, and the flight attendant exposes Monk as the passenger that is causing her a lot of trouble, normally Sharona would step in in these type of situations to convince whoever with her voice of reason that Monk is indeed a famous detective and sought after consultant for the SFPD. Her silence in this situation and later when the flight attendant confiscates the lighter and takes the glass with the evidence residue is incredibly out of character. (00:30:40 - 00:32:30)
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