Other mistake: When Stottlemeyer is about to eat his cake he is looking at Monk. Shortly before he starts to pick up a piece of cake you can see he is pretending to chew a piece in his mouth. Throughout the scene you can see Stottlemeyer's face and the cake. At no point before he pretends to chew does he put a piece in his mouth.
Other mistake: In the scene where Mr.Babcock is murdering the woman in the cinema, we see the woman has a big bucket of popcorn. As he starts strangling her, only a small amount of popcorn falls out. When the camera turns toward the floor there is a lot more popcorn on the floor and it it is spread right across the screen.
Other mistake: When Monk is leaving Derek Philby's classroom, he dots the "I" in "REMINDER" on the blackboard. However, the word was in capital letters, so the "I" needn't have been dotted. Monk wouldn't make this mistake. (And the word is written in plain block sans-serif letters, so he's not adding a missing line: he's definitely dotting the capital I.)