Mr. Monk and the Sleeping Suspect - S2-E7
Deliberate mistake: All the mail bombs are delivered in packages tied with knotted string. The USPO hasn't allowed string-tied packages since the mid-90s (they get caught in automated equipment), but since the knots were crucial to ID-ing the suspect in this episode, that fact had to be ignored.
Mr. Monk and the Sleeping Suspect - S2-E7
Continuity mistake: When Monk spills the potted plant and grabs a vacuum cleaner from the hall, he's holding the handle with several large paper towels. When he plugs the vacuum in, he now has a wipe in his hand instead. When he's finished plugging in and turns around, the wipe has vanished and there's nothing in his hands or on the vacuum. But when we cut to a wider shot as he turns the vacuum on, the paper towels reappear on the handle.
Mr. Monk and the Sleeping Suspect - S2-E7
Continuity mistake: Monk throws the bomb into the toilet and shuts the door, pulling it towards him. When we see him hit by the blast there's no door in the way, and in the reverse shot looking into the bathroom the door has swung open into the room again, despite the blast radiating outwards. Plus it should have destroyed the door anyway.
Mr. Monk and the Sleeping Suspect - S2-E7
Plot hole: Technically, Brian Babbage's plan would never have worked due to the fact that all outbound mail goes to a main post office from the local post office and then placed through scanners to determine the contents, which would have inevitably exposed the bomb inside.
Mr. Monk Meets the Playboy - S2-E8
Continuity mistake: Dexter places the sapphire necklace on Amber at a completely crooked angle. When the shot cuts, though, it has instantly straightened and centered itself.
Mr. Monk and the 12th Man - S2-E9
Visible crew/equipment: When Monk is talking to Dr. Kroger about Sharona's new boyfriend Kenny, you can see the cameraman's reflection in the window behind them. (00:09:26)
Mr. Monk and the 12th Man - S2-E9
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.
Mr. Monk and the 12th Man - S2-E9
Plot hole: Monk identifies the killer because of a shirt sleeve that gets ripped off... he noticed the button is sewed on in a unique manner with the threads parallel as opposed to the "standardized" crisscross pattern. The killer and Monk coincidentally use the same dry cleaner and Mrs. Ling sews buttons parallel because it's her style. Dialogue in the episode indicated she is the only one who sews buttons on like that. But I checked over 20 button up shirts here at my house and the ratio of crisscross to parallel button sewing methods is 50% of each - hardly some unique identification method.
Mr. Monk and the Paperboy - S2-E10
Continuity mistake: When Monk says "I can bench 200", you can tell he has his arms by his sides, but in the next shot, his hands are held up at the level of his waist. (00:12:15)
Mr. Monk and the Paperboy - S2-E10
Deliberate mistake: When Sharona spots Disher's personal ad in the newspaper, there is a shot of it. She then reads the description of him from the ad, which matches what's on the screen, however, the second part she reads, "Seeks petite blond with no-nonsense attitude, kids ok" is not in the ad shown. (00:22:20)
Mr. Monk and the Paperboy - S2-E10
Continuity mistake: Stottlemeyer says "does that make any sense to you?" as Monk is straightening the pots on the mantelpiece - all the lid handles are horizontal. The camera cuts away for a second, cuts back, and the lid on the far right has suddenly rotated 90°, whereupon Monk straightens it to be horizontal like the others.
Mr. Monk and the Three Pies - S2-E11
Continuity mistake: When Van Rankin shoots his wife, the black gym bag, which has been slung over his shoulder since he entered the kitchen, disappears between shots. (00:31:05)
Mr. Monk and the Three Pies - S2-E11
Continuity mistake: When Van Rankin takes the borrowed flour from his kitchen counter and hands it to Sharona, it's in a standard paper flour sack, and the counter is clean. Later, there's flour dust on the counter and the impression of a large, round flour tin - like the one in Monk's kitchen - instead of an imprint of the paper sack. (00:37:20)
Mr. Monk and the Three Pies - S2-E11
Factual error: In this episode, when Sharona and Monk arrive to visit his brother, they talk about the swing set. Monk tells Sharona that his father put up the swing when he was 8 years old but this is a much newer swing set. Look at the curved plastic seats: these have come about in the last six to eight years. It also doesn't look at all rusty like a 40 year old swing would.
Suggested correction: Ambrose is obsessed with leaving the place "exactly the way dad left it for when he comes back." Hoarding old newspapers for him would be a character mistake, but things like keeping the old swingset maintained and up to current safety regulations so everything's perfect "when he returns" would be a thing he'd find to do around the house. His agoraphobia might not be so bad in the yard. Alternately, he could pay someone for yard upkeep, which would include the swingset.
Mr. Monk and the T.V. Star - S2-E12
Continuity mistake: The blood stains on Brad Terry's sweatshirt change positions after he runs back into the house. A few shots later, they're suddenly so faint they're barely visible at all anymore. Blood stains don't fade, at least not in just a few minutes.
Mr. Monk and the T.V. Star - S2-E12
Plot hole: Unless I missed something, the killer didn't wipe his prints off the knife he used to kill his ex-wife.
Mr. Monk and the Missing Granny - S2-E13
Continuity mistake: In this episode Randy is allergic to cats, in fact he has an allergic reaction even if a cat has been there lately but is not there now. But in Mr. Monk and the Sleeping Suspect, during the scene where Monk and the police are investigating the woman's destroyed house, a cat passes within a few feet of Randy, who doesn't sneeze or show any signs of his allergy.
Mr. Monk and the Missing Granny - S2-E13
Continuity mistake: Monk identifies the kidnappers' house by the pizza box outside by the bin. In the wide shot it's upside down on its corner, with "zza" just visible behind a black bag. In the closeup it's turned around, so we can see more letters, and it's moved.
Mr. Monk and the Captain's Wife - S2-E14
Continuity mistake: In the scene where Sharona returns the dog, she opens the gate, turns around and closes & latches the gate. They even make a point of showing the latched gate before she is on the porch. As she is talking to the owner, you see the gate behind her open and then closed between shots. She had latched it, so all scenes should have shown it latched.
Mr. Monk and the Captain's Wife - S2-E14
Continuity mistake: In the pre-credits sequence, Karen attaches a clip to the right side of Leland's shirt, but a few seconds later, there is none on his right side. They are all on his left side. They also disappear and reappear.