Mr. Monk Goes Back to School - S2-E1
Continuity mistake: When Monk is leaving Derek Philby's classroom, he is quite content to just pick up a piece of chalk (with his bare hands) to write on the blackboard, but earlier, he makes sure to use a chalk holder to do this and nearly has a panic attack when he gets chalk dust on himself.
Mr. Monk Goes Back to School - S2-E1
Continuity mistake: At the school tower murder scene, Randy's coat is buttoned up over his tie, but changes suddenly when Stottlemeyer says, "OK, bring him up." The coat is immediately unbuttoned and open all the way in the very next shot.
Mr. Monk Goes Back to School - S2-E1
Continuity mistake: Mr Monk completes his name on the chalk board at the beginning of class, but when class is dismissed the 'k' in Monk is incomplete.
Suggested correction: After he wrote his name, he says "what's up with that k?" and erases it. He started to re-write the k when he got hit by the eraser, leaving it unfinished.
