Factual error: Whenever the killer (always dressed in black with a balaclava disguising his/her identity) uses a knife, the blow invariably is an overhand strike. However, a knife in a downward thrust quite frequently simply skids off the overlapping ribcage of the victim.
The Killings at Badger's Drift - S1-E1
Visible crew/equipment: After Barnaby and Troy question Michael Lacey at Holly Cottage and leave, it then cuts to Michael entering his painting studio, and while the camera is tracking backwards, the reflection of the short-sleeved camera operator becomes visible in the mirror atop the dresser, at the right side of the screen.
Revealing mistake: The actor who dies in this episode moves his eyes when Sgt. Troy lifts his eyelid. (01:06:20)
Plot hole: Several shots show Barnaby reviewing a newspaper announcing a new death in Strangler's Wood, the Brazilian Woman. No one supposedly knows who she is, as the article states, but the photo of the dead woman is a professional headshot from when she was alive. How could they have obtained her headshot if no one knows who she is?
Suggested correction: She had it with her, as she was a model/actress.
Continuity mistake: When the police unearth the body of Ms. Bennett, she is deep in the hole where she was interred. However in the flashback, the killer dumped her into a really shallow grave, in fact most of her was exposed.
Continuity mistake: When Frances Le Bon is climbing over the locked church gate to investigate why bells can be heard coming from an empty church, she is wearing a skirt. When she walks out of the church with Barnaby shortly afterwards, she is wearing trousers.
Murder on St Malley's Day - S5-E4
Plot hole: In the Pudding Club episode, when they visit the secret room, all the candles are lit even though no-one is in there.
Continuity mistake: During the scene Gavin Troy drives to the crime scene with Tom Barnaby as a passenger in Troy's Rover 45. When they show the car passing by with a higher speed after a cut at the ending of this scene, it is Tom Barnaby's Rover 75. (00:04:30)
Visible crew/equipment: Tom kneels to pet a fox, at which point one can see a human hand holding the fox in place for the actor. (00:06:35)
Bad Tidings - S7-E2
Continuity mistake: When Helen Grace is in the retired GP's house choosing which apple she will eventually stuff in to her victim's mouth, her hand wavers over one apple, but instead chooses another. At the end when we see a flashback of that scene, she picks up the first apple she was originally going for.
Revealing mistake: Dead lady blinks when Barnaby enters the room.
Continuity mistake: In the first episode of season 10, when Marissa is holding a dog while talking to Elaine, the way her arm lies around the dog's neck changes several times between shots.
Other mistake: At the start when the Lexus is found it is shown as a mirror image as can be seen by the badge and registration number. (00:03:57)
The Made-to-Measure Murders - S13-E2
Visible crew/equipment: A crew member's shadow is seen moving behind an open door that a character is walking by. (00:15:45)
Factual error: A bike rider is warming down on freestanding rollers and is apparently thrown off when an assailant sticks a wrench in the front wheel. That is not how physics work. If a bike is in motion, the forward momentum of the bike and rider will absolutely throw the rider head over heels. But on freestanding rollers, there is no momentum. The bike and rider are standing still and only the wheels are moving. The rider will, of course, topple off but not be thrown.
