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: Notice also that in the opening credits scene when he is touching parking meters her also wipes his hand on his clothes each time he does it.