Mr. Monk and the Employee of the Month - S3-E7
Plot hole: Monk wants to take a look at the case that got Christie to leave the force. But given that they are ordinary cops they would not be able to just go and pull internal affairs files.
Suggested correction: I'm not sure what you mean by "ordinary" cops. Captain Stottlemeyer is the one pulling the file. Plus, we don't see what they had to do to request access the files. There's no indication they just went in and randomly pulled the file with no authorization.
Mr. Monk and the Panic Room - S3-E2
Continuity mistake: Whilst Randy and Sharona are in the kitchen feeding the monkey you can see near the start of the shot that Randy has his right arm leaning against the kitchen counter top. In the next shot his arms are suddenly folded.
Mr. Monk and the Game Show - S3-E8
Continuity mistake: When Monk is telling Dwight how the guys are cheating, he holds the green sachet with one hand, but in the next shot, he is holding it with two. (00:32:30)
Mr. Monk Gets Cabin Fever - S3-E12
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.
Mr. Monk and the Girl Who Cried Wolf - S3-E6
Continuity mistake: About midway through, the new nurse is sitting on Monk's kitchen counter eating a sandwich. She puts the sandwich down on a plate as she hops off, the shot switches to another angle to include Monk as she walks away, and the sandwich has suddenly jumped off the plate and is now lying on the counter a few feet away. Neither of them had time to pick it up or move it.
Factual error: As Monk is removing the crumbs off the keyboard, he flicks one crumb away from the backspace key. It gets flicked up and lands near the 0 button on the numeric keypad. Yet when this happens, the screen then says "Do you want to delete files?" as if he hit the delete button.
Mr. Monk and the Blackout - S3-E3
Visible crew/equipment: During the police investigation at the power station, the shiny blue construction helmets show us the stage lights, reflectors, camera and film crew several times. (00:09:00)
Mr. Monk vs. the Cobra - S3-E11
Continuity mistake: After Monk has been found in the coffin, Natalie and the captain comment on his smiling and the camera shows the candle has melted down all over Monk's hand. Then when the camera comes in closer, the candle is whole again and monk's expression has changed a little from the previous shot.
Mr. Monk Takes His Medicine - S3-E9
Continuity mistake: When Monk is eating dinner, he spills ketchup on his shirt, but in the next shot his shirt is clean.
Mr. Monk Takes Manhattan - S3-E1
Continuity mistake: When Monk is lost in the street crowd after getting pushed into the subway car, his left shirt collar is sticking up over his coat. It's still up when he puts his hands to his head, but is tucked neatly back in in the next shot, though he still has both hands on his head. A few seconds later, it's the right collar flap that's sticking out instead.
Mr. Monk Gets Stuck in Traffic - S3-E13
Continuity mistake: In the beginning of the episode, right after Ray Galardi kills Steve Marriot, Galardi puts him in the passenger side door of his VW Beetle and drives him up inside the dump-truck. Galardi puts him in the VW driver's seat, and walks around to the other side of the Beetle. This is all well and good, but, Marriot's head switches positions from the time when Galardi puts him in the car to the time he walks around and starts the engine.
Mr. Monk Gets Stuck in Traffic - S3-E13
Revealing mistake: The VW Beetle that slides out of the dump truck and rolls over is noticeably not the same car the victim was driving earlier. It's a lighter color, and is already badly dented, even before it's wrecked.
Mr. Monk Takes His Medicine - S3-E9
Continuity mistake: In Stottlemeyer's hospital room, a medicated Monk finishes off the leftover pudding from the food tray. Then, while he's talking to them, the pudding smeared on his upper lip disappears and reappears between shots.
Mr. Monk and the Panic Room - S3-E2
Continuity mistake: Darwin the chimp pulls a large blue bowl from Monk's kitchen cupboard and throws it on the floor, breaking it. We cut to a close-up of Darwin spinning, then pull back as he starts pulling out glasses - and the blue bowl is back on the shelf, intact. When the angry landlord enters, Darwin pulls the same bowl from a different shelf and throws it again.
Mr. Monk Takes His Medicine - S3-E9
Continuity mistake: During Monk and Sharona's race to the armored car robbery scene, the red Mustang's rear-view mirror disappears. When they arrive, though, it's back in place on the windshield. (00:36:30 - 00:38:30)
Mr. Monk and the Panic Room - S3-E2
Deliberate mistake: All the dishes that are usually neatly arranged in Monk's kitchen cupboards (pots, pans, stacks of plates etc.) have been replaced here by cheap plastic ware, so that Darwin the chimp can pull them all out and throw them. Though we hear shattering-glass sound effects as they supposedly hit the floor, the dishes Darwin bangs together and throws are very obviously plastic.
Mr. Monk and the Red Herring - S3-E10
Continuity mistake: At the science fair, after Lyle Peck lights the poster on fire he puts the Bunsen burner onto the table a little away from its original position but when the camera angle changes it is back where it originally was, under the beaker and stand.
Continuity mistake: In the opening sequence, the uniformed cop who finds toddler Tommy holding the severed finger bends down and says, "What've you got there, big guy?" In full shot, the cop is bare-handed. But when we cut to a close-up in the middle of his line, he's suddenly wearing a latex glove.
Mr. Monk and the Girl Who Cried Wolf - S3-E6
Visible crew/equipment: Nurse Davis swings open Disher's car door at the end, and captures a reflection of the camera and the entire film crew standing nearby. (00:40:40)
Mr. Monk Takes Manhattan - S3-E1
Factual error: The .22 caliber shots would be a higher pitch.