Episode #4.6 - S4-E6
Plot hole: The killer is able to dupe the victim into hiding at the back of a car promising that they will bring a certain someone on a bench and get them to talk about a very bad thing they've been doing, so the designated victim can record the conversation with their phone. This requires the victim to be outrageously stupid; the car, with a closed trunk the victim is hidden in, is parked at distance from the bench; the microphone of her phone would never record that far, and nobody would believe their own phone can work that way, especially when they can hide the phone in a sports bag by the bench, the bushes, the gaps in the bricks or just demand that their supposed friend carries the phone herself. Also, the killer couldn't be sure that the device wouldn't say something about what they were doing (as often happens before you start a recording; you state the time, place, purpose of the recording, plus all the other content of the phone she didn't have time and chance to review!), but makes no attempt to make the phone disappear.
Episode #4.6 - S4-E6
Continuity mistake: When JP announces that the SIM card was sold in Isla Jonas, Dwayne in the foreground is holding his hands on the buckle of his belt the opposite way compared to the wider angle. (00:36:25)
Episode #4.6 - S4-E6
Continuity mistake: At the end of the episode, in a stellar endorsement of Catherine's hospitality JP says that it's better than the prison cell. During the sequence Tobi Bakare's hands are on/off the bottle repeatedly. (00:50:25)
Episode #4.6 - S4-E6
Continuity mistake: Maz Shipley confesses to the bribe and says it was "For Mum." Her teammate looks away from her, but in the next shot she is still looking at her and turns her head only after. (00:33:55)
Episode #4.6 - S4-E6
Continuity mistake: In the shot when Dwayne boasts about knowing most of the bookies on the island, DI Humphrey Goodman in the foreground has his hands on his waist, in contrast with the shot before and after - arms relaxed down his sides. (00:32:25)
Episode #4.6 - S4-E6
Continuity mistake: Rewatching the footage of the previous games, Humphrey says that there's another match where the opponents dropped the ball. He is in foreground with his hand on his cheek, but in the close-up of Florence that asks to rewind, Kris Marshall's face is clear. (00:31:35)
Episode #4.6 - S4-E6
Continuity mistake: When Florence says Humphrey's usual line about needing a break after a long day, Joséphine Jobert puts her hand on her forearm, but it's in the air in the reverse shot. (00:27:50)
Episode #4.6 - S4-E6
Continuity mistake: In the interview with the Saint Marie team, about the complaint the victim was about to make before the disciplinary committee, Alison Turner has the hands on and off the water bottle as the different camera angles alternate. (00:25:20)
Episode #4.6 - S4-E6
Continuity mistake: Goodman asks the suspects if anyone saw Shelley earlier that morning. Alison Turner has her fingertips against her temple, but it's a closed fist in the next shot. (00:14:40)
Episode #4.6 - S4-E6
Continuity mistake: Inspecting the hotel room, Florence pulls the money out of the wallet holding it at a certain distance in the first shot, much closer/partially still inserted in the reverse. (00:11:30)
Episode #4.6 - S4-E6
Continuity mistake: Florence tells Humphrey poolside that the victim was "stabbed in heart. Death would have been instant." Goodman in this wide shot listens with his hand a bit lowered, placing it just below his chin, but it's in front of his belly in the next shot. (00:09:25)
Episode #4.6 - S4-E6
Continuity mistake: Humphrey and Florence are at the resort, and she just laid down the preliminary forensics reports. Dwayne calls their attention; Florence leans against the railing with right hand and puts the left one on her hip. Except, the next shot she is leaning on the railing with both. (00:10:00)
Episode #4.6 - S4-E6
Continuity mistake: The police is at the crime scene for the first time; the victim has her phone lying horizontally on her arm, but in close-up the hand dropped lower and the phone now is at 45°. (00:06:40)
Episode #4.6 - S4-E6
Continuity mistake: After the desk accident, the phone ring at the Honore police station. Florence is looking at her boss puzzled holding the cup in one hand, except in the intermediate overhead shot, when she is using two, and again she goes from one to two all of a sudden when she asks Dwayne about the call. (00:06:25)
Episode #4.6 - S4-E6
Continuity mistake: First shot right after the opening theme; Dwayne is holding the Saint Marie Times and his hand is on the box above what we see in close-up is an article about the recession. In that close-up though, his hand is much, much lower on the page. (00:05:00)
Episode #4.6 - S4-E6
Continuity mistake: The victim is discovered. She is holding her phone in close-up in a direction that seconds the fingers, but in the aerial shot the phone comes in from the opposite direction, left to right. (00:04:25)
Episode #4.6 - S4-E6
Continuity mistake: The coach of the winning duo looks in the distance at the other volley players leaving. His glass is noticeably fuller in the slightly out of focus reverse shot. (00:02:30)
Episode #4.6 - S4-E6
Continuity mistake: In the establishing shot of the serve of the matchpoint, the corner of the field is free from shadows and the people standing in the opposite corner cast long shadows. In the following shots, both these conditions change. (00:00:20)
Episode #4.6 - S4-E6
Continuity mistake: Dwayne is holding the telephone to play the recorded message in two different ways between shots. (00:19:05)
Episode #4.6 - S4-E6
Revealing mistake: Florence passes a mug of coffee to her boss, who goes on to sit in his chair and have a tragic overacting accident. However, when things were still normal and he merely approached the desk, you could see Florence already stop drinking and frown preoccupied before anything bad happened. (00:06:10)
Answer: There's probably no particular reason. Sets and props on long-running TV shows often change as needed and for various reasons throughout a series run.
raywest ★