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)
Character mistake: In the first scene in the office of the dead banker, Jack is not wearing any gloves and touches the cufflink box freely without any precaution. (00:04:40)
Continuity mistake: The detectives are discussing the presence of the cufflink. Humphrey asks if "He's taken his own life in remorse", and the camera cuts to the deceased. Notice an iPhone on the desk by him. A moment later, the phone rings and Humphrey has to search the victim's pockets to come up with the phone. (00:04:55)
Continuity mistake: In the intro, Dominic Green greets the client from Saint Marie. A few people are passing by the car when he opens the door, but when he closes them those people vanished in thin air. (00:01:55)
Continuity mistake: Humphrey puts on the banker's desk the printed article that establishes him as an old friend of the victim. The paper is in a different spot of the desk depending on the camera angle - you can easily tell by the upper left corner of the sheet, that either juts out from the other papers on the desk, or is properly on top of them. (00:45:10)
Revealing mistake: The photo found by JP in the newspaper archive is photoshopped so badly that you can actually see the line where Julian Wadham's face has been pasted onto the sailor's head. (00:44:55)
Continuity mistake: JP is interviewing the widow. When she is reacting to the latest questions, her hand is open in the frontals, closed in the rear views. (00:37:00)
Continuity mistake: Jack tells the silly story of his cuff-collecting, one-armed uncle; in the reaction shot, Humphrey is sitting with his left arm up in a recognizable position, which changes in the next shot. (00:35:40)
Continuity mistake: Jack sits at the conference table, next to Florence. She moves the hand away from the notepad, but it's back on it at the cut. (00:34:20)
Revealing mistake: Dwayne turns the volume of the computer in DI Jack Mooney's office; when we start hear him, the volume has gone up just a few notches, but it's already just as loud in the end as it is when Dwayne finishes to set it. (00:29:10)
Continuity mistake: In the Scotland Yard office, DI Humphrey Goodman turns around and finds the teleconferencing DI Jack Mooney on screen. He announces to the team "I think I may have found him", and turns around, holding the phone closer to his chest. The movement is repeated in the next shot. (00:28:50)
Continuity mistake: A business card from CityMet Bank comes into play. Humphrey points at the whiteboard with the card, but in the next shot the card becomes a magic marker. (00:23:00)
Continuity mistake: Humphrey passes the bridge and meets by chance the distressed ginger; when he startles her, the phone instantaneously switches from right to left hand. (00:03:40)
Continuity mistake: During Dwayne's annual appraisal, Humphrey holds a bic pen that faces different directions in the reverse shots (easy to tell from the cap being on opposite sides). At the end of it he removes his hand from the desk, but it is back at the middle of the questionnaire in the next shot. (00:00:50)
Character mistake: Florence says that Commissioner Selwyn Patterson and Martha are halfway through the bottle, but the bottle is practically empty. (00:29:55)
Continuity mistake: Evening at Humphrey's; Goodman and the two French main characters are looking at the unlikely pair of the Commissioner and Martha being drinking buddies. Florence is looking over her left shoulder in a pinup pose, but she is turned right in the reverse shot. (00:29:45)
Other mistake: In the bank statement that Dwayne hands to the DI, there are cash withdrawals "from the past three months", with the past three months being January, February and...February, again. (00:20:30)
Continuity mistake: Goodman rushes out of the police station after spying someone tampering with the jeep. First time we see the various market stalls in front of the station, and two women are moving from one stall to another; one of them is wearing a sleeveless pink dress and has her hair in a bun. Humphrey arrives by the jeep in the next shot, and the two are back to the same stall they departed from earlier. (00:17:35)
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 ★