ludicrous conclusions

Interesting you mentioned season 5. I watched recently ‘Mr. Monk is on the Air’ from that season. This is the episode in which a radio shock jock planned to get his neighbour’s dog (who he had trained) to come in to his house through an open window and open a gas tap to kill his wife. This was while she was sleeping. The dog would turn on the tap upon him hearing him say, over the radio, something like "Shiver me timbers". The problem was that he said the command multiple times, for no good reason.

The dog would logically then be going multiple times in the house to try to turn on the tap, and would then get killed by the gas, which was obviously not part of the plan. Also, the dog could not have been trained, I don’t think, to immediately leave the house once he turned on the tap. This was because he lingered around to take a shoe, the evidence which ultimately incriminated the murderer.

For me, some of the ludicrous plots or amazing leaps of logic that Monk makes are part of the show.

I see this as more as light-hearted, almost comedic show. A lot of the explanations of how the crime was committed are far-featched, but that's kind of the point.