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: 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.