Tom's humor is omnipresent on Monk, but since his humor is as wide as the ocean, the comic bone he pulls on Monk is so vastly different from his preferred mode of driving a call-in show, you don't often recognize it. I also assume he is funny around Jillian Barberie, but I doubt if he screams "GET OUT OF MY HOUSE" at her all that often.
Umm, I meant, why do you think Tom has anything to do with Monk other than supplying fine corrugated products? Now, it IS some of the funniest cardboard in the business.