Other mistake: Days in the series seem sometime to go on for unusually long amounts of time. In this episode, there's the exact opposite; the murder happens at 10 AM (which already seems awfully late for the opening of an election), the police obviously are called right away, Jack and Florence go to the station to discuss the case, and then all of a sudden it's a wrap when Dwayne and JP get back there with their findings. Unless they have searched the businessman's residence for over 6 hours while Jack and Florence have been doing next to nothing at the station, it makes no sense.
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)
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: 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: Fire exit scene. Everyone turns around surprised by Jack's appearance in the opposite direction. Florence turns twice, though. (00:07:20)
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: 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)
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.
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
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
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
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: 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
Continuity mistake: Dwayne pulls up from the evidence box the gun used for the murder; he holds it at the bottom part of the handle, but he his holding it with a finger near the trigger in the next shot. (00:05:30)
Other mistake: The police boat approaches the scenes of the crime coming in from the right, in a straight line, then in the proximity of the boat they turn around it, moving clockwise, passing in front of the bow and then to the left side. When they review the readings though, the icons show a completely different story, as if the police boat approached from behind and they boarded docking right at the stern. (00:04:40 - 00:08:00)
Continuity mistake: When Martha says "Yes" to Humphrey, the waiter in the background has his hands free. She kisses him in the next shot, and in order to clap with the others the waiter has to put down two wine glasses he was holding. (00:49:45)
Continuity mistake: At the pub towards the end of the episode, Jack brings a glass of rum to Dwayne. He hands it to him with his left, but you can see in the shot when he begins to get seated that it's the right arm that he has extended. (00:48:10)
Revealing mistake: Humphrey and the team receive the decisive last clue from Saint Marie; on the Scotland Yard PC, in the inbox there are tons of emails marked as 'today' that come from places like the Guadeloupe lab and instead days old. (00:34:35)
Continuity mistake: Up to the point when Martin West says he took the gun to 'impress the lads', Florence has her hair to the right of her face going in front of the shoulder. New shot, and there's much of it combed back, and it keeps going back and forth until it's again all in the front in Florence's next close-up. (00:26:15)
Character mistake: The first term served by Dwayne's father is typo'd as 4 RS instead of YRS. (00:15:25)
Answer: Most likely they had only tropical exotic drinks, he wanted an old fashioned English beer.