Mr. Monk and the Genius - S7-E2
Plot hole: Kloster's plan of switching the headstones wouldn't have worked because cemeteries keep records of who's buried in which plot. Before exhuming the body, the records would have been checked and someone would have noticed that the name on the headstone and the name in the records didn't match. (He might have broken into the office and changed the records, but it's never brought up, so he likely didn't.)
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.