In the Footsteps of a Killer - S6-E7
Continuity mistake: Jack recovers from Nadine Hunter's belongings a little bag containing hair. His fingers are in the middle of the bag in some shots, on the left corner of it in others. (00:15:00)
In the Footsteps of a Killer - S6-E7
Character mistake: Jack asks which one of the two saints is the Saint Ursula venerated in Saint Marie, and mentions the Ursula martyred by the Huns, and Ursula Micaela Morata, with the gift of bilocation. Being this thoroughly informed, he should know that the second is not a Saint, but a Venerable. (00:17:20)
In the Footsteps of a Killer - S6-E7
Continuity mistake: During the interview at the bar, the quantity of coconut and rum in Tony Garret's glass changes between shots multiple times. Easiest bit to spot it is towards the end when he brags that he could find a dozen witnesses in an hour; as he says that line, the liquor barely covers half of the ice cubes, but after a brief cut on Ardal O'Hanlon, the glass is full enough to cover most of them. (00:26:00)
In the Footsteps of a Killer - S6-E7
Continuity mistake: The forensics team consisting of JP and his DJ cousin has produced the magnified audio of the background noise featured in the taping. Everyone turns then to the whiteboard, but Florence's hand position on her mug does not match in the different shot shots (thumb on or off the rim, mug raised as she drinks, mug in front of her chest). (00:31:20)
In the Footsteps of a Killer - S6-E7
Factual error: In the denouement, DI Jack Mooney says that all the suspects could prove they were not in the building on Thursday June 22 2009. Which was a Monday. (00:41:10)
In the Footsteps of a Killer - S6-E7
Plot hole: Spoiler. The killer needs to get rid of two women. One is his mistress that he just dumped and is acting psychotic about it, the other is his wife. He kills the wife and makes it look like it was his mistress to murder her. So she goes to jail, where she will die two years later due to pneumonia...and in all this time, she never once says anything about the affair! He has been extraordinarily lucky, because had she said anything, and she had absolutely no reason not to in her circumstances, the case would have not been so open-and-close, they would have considered the idea that he could have been an accomplice, but even assuming the past detective (which DI Richard Poole called a good detective) was a total fool, at the very least Jack and his team would have found a trace of this controversial alleged affair in the files and solved the case much earlier. But no, the plan was to send his mistress to jail and that somehow made her cease to be a threat to him, when instead she'd have been much more dangerous to him.
In the Footsteps of a Killer - S6-E7
Plot hole: Somehow, Jack is so lax in his investigation that he does not ask any detail about the sales representative supposedly the husband had an affair with and that he ended (which could have very well been a suspect nobody considered before, since he ended the relationship to stay with his wife...had she existed, but Jack can't know that he's lying!), but has acquired DNA from Ian Matlock to run an overnight test on the hair sample (which we have to assume was complete with follicles and still in test shape after 8 years in a bag).
In the Footsteps of a Killer - S6-E7
Plot hole: The original murder went unnoticed because of extraordinary incompetence of the police; even if they did not have the ingenuity to extrapolate the background noise, they still had to investigate how a murderer would have gotten away with a corpse in the middle of a carnival, but the issue is never raised. More importantly, the last phone call of the victim came from a place 40 minutes away from the city, which would mean a different cell tower - and since they needed to track down the body that never turned out, monitoring the phone the last call came from is standard procedure.
Continuity mistake: At the beginning of the episode, Edwina Bousquet scoffs at the apology and gets up. Close-up of Judith Dawson, and you can see for a second in the background the bike with Danny John-Jules entering the premises. But there is no sound effect for it and in the next cuts he's nowhere to be seen; he arrives only later. (00:00:25)
Continuity mistake: Catherine is chatting with the not-so-bad candidate, who offers his support. She says "I'd like that" with a bit of her scarf that goes in front of her shoulder, unlike the previous shot. (00:01:45)
Continuity mistake: DI Jack Mooney arrives on the scene of the crime. He is walking with his left hand on his chest in the first shot, but viewed from the side, his arm hangs low. (00:05:25)
Continuity mistake: Fire exit scene. Everyone turns around surprised by Jack's appearance in the opposite direction. Florence turns twice, though. (00:07:20)
Continuity mistake: After Judith Dawson's first testimony, Jack thanks her; Florence is just pretending to write and stops, but in the next shot she is back at it, scribbling her pad with the pen. At the end of this new shot, she stops writing, but is writing again in the next, all while DI Jack Mooney talks in continuity. (00:08:55)
Continuity mistake: Back at the station, Jack picks Peter Baxter's profile off Florence's pile. Action happens in two shots, and the marker in his hand does a 180°; black cap up/black cap down. The mistake happens again later, with Catherine's picture. (00:10:50)
Continuity mistake: Jack receives the photos of both Reverend Matthew Dawson and his wife; during the sequence, the black marker switches hand from right to left, to right again, and is pointing sometimes up, sometimes down. (00:11:20)
Continuity mistake: When Florence "Ehh!"s and "Shh-shh!"s Dwayne, she does it with one hand, which becomes two at the next shot. (00:13:00)
Revealing mistake: The photo from the high school years of Edwina and the candidate is a photoshop Frankenstein where you can see the face of the actress pasted on someone else's head. (00:24:50)
Continuity mistake: Dwayne is staring at the boards after his superiors have gone to the church function. He says "JP..." and his younger coworker has his pen on the paper, but at the cut the pen hand is scratching his nose. (00:34:00)
Plot hole: When we see the murder happen in flashback, the killer stabs the victim wearing no gloves whatsoever, nor wipes the handle. In a very sportsman conduct, the victim also decides not to literally scream bloody murder as he gets stabbed, nor make any sort of sudden, noise inducing movement that would have instantly exposed what was happening. He gives their killer, apparently, all the time to go back to their accomplice before Catherine notices the blood pouring on the floor - how rude of him to silently bleed all over the booth without cleaning after himself. (00:41:45)
Plot hole: The murder happens where and when it happens because the candidate "is a very busy man", and apparently then the best course of action to kill him is doing it while he is casting his vote. At this operation, involving the other 2 candidates for the role, there is no press nor any normal voter, for no reason - not safety since Dwayne was not expected. Had they introduced the rich Victor Pearce as some sort of mobster surrounded by bodyguards, it would have been an acceptable plot idea, but the guy travels with his son as sole member of the staff and nothing about his characterization leads the viewer to believe that the only chance to murder him is for a rotund 62 years old lady in clogs to perform a Metal Gear stunt sneaking in undetected while a priest is facing the other way for 5 seconds and pray that nobody else shows up at the voting booth and all the others are taking their time to put a cross on a piece of paper.
Answer: Most likely they had only tropical exotic drinks, he wanted an old fashioned English beer.