Mr. Monk Goes to Jail - S2-E16
Plot hole: It is unrealistic that a prison cook who did not punch out would not be missed or found until the next day, especially after a lock-down scenario as portrayed in this episode, where a meal has been poisoned - likely in that very kitchen.
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.