Mr. Monk Goes to the Dentist - S4-E15
Continuity mistake: When Randy is at Monk's place talking about hiring him, Monk says "Like who?" to which Randy replies "Like Me". While Randy says this he is holding a glass with one hand, the other being in his pocket. In the next shot, when Natalie says "Is it about the dentist?", Randy is holding it with two hands. Then, in the next shot, he is holding it with one hand again.