Happy Birthday, Mr. Monk - S8-E9
Continuity mistake: When Monk pulls all his drapes shut, there's a wide gap in the right hand set that's letting at least five inches of bright sunlight through. No one has touched them again, but when Natalie goes to open the drapes a few moments later, the gap has completely closed itself. (00:16:00)
Happy Birthday, Mr. Monk - S8-E9
Continuity mistake: After Cowboy Hank twirls his guns, his arms are raised. When it cuts to a shot from behind his back, his left gun is in its holster and his arms are still raised. He then holsters his right gun. (00:39:05)
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.