Continuity mistake: When Aunt Mary is writing on the whiteboard at the hospital, the word "killed" changes style between shots. (00:31:40)
Visible crew/equipment: When Mr. Jenkins arrives at the hotel at the end, a light screen is reflected in his sun glasses. (00:43:05)
Continuity mistake: Commissioner Selwyn Patterson puts down at the end of the episode a deck of cards and the glass with his drink. He then helps Aunt Mary up, and with the table again in view, both the deck and the glass shifted to the right by a couple of tableboards. (00:44:50)
Continuity mistake: When at the end of the denouement Neil Jenkins and Freddie Hamilton are face to face, the tears that were running all the way down the face of the actor have been wiped clean, leaving just a bit below the eye. (00:45:10)
Continuity mistake: When Humphrey opens the bag, various items fall on the table including a small trophy cup, which lands perfectly vertical on its base. In the subsequent close-up of the messy table, the cup is lying down, and all the various items (look at the conch) are just scattered around differently than before. (00:45:00)
Other mistake: Humphrey's flashback when he is on the balcony of the room is about a sentence he never heard, since the second interview was done by Florence and Dwayne.
Continuity mistake: Ella, when asked, says that she does not know about the money, and leans back with her left hand on the lounger - but she has her arms in her lap in the next shot. (00:32:20)
Continuity mistake: Neil Jenkins starts spilling the beans about being previously acquainted with Robert Daws' character. Right before the flashback when he meets him at the hotel, he is putting the towel around his wife's shoulders, at the edge of the frame. Several seconds later, after finishing the story, his wife is sitting on the lounger and he puts the towel around her shoulders again, this time with better framing. (00:32:30)
Continuity mistake: Neil Jenkins is sitting while his wife is swimming in the pool. She comes out; notice Jenkins' left arm and his watch; the watch faces towards Dwayne when he asks "So why did you lie to us?", towards his right when he answers. (00:33:15)
Continuity mistake: The white lid of Humphrey's soup changes position between shots; it sticks out from the board during certain close-ups (like when Catherine cautions the police people or Aunt May says "nuts to that"), not so in the wider angle. (00:26:00)
Continuity mistake: Goodman is at the hospital, tasting the soup famously loathed by his predecessor DI Richard Poole. Florence opens the door with her right, and the case file folder in her left. Cut, and the folder is in her right, rolled. Cut again, and she's holding it straight. (00:25:50)
Continuity mistake: When JP picks up the passport of the victim, in close-up he holds it with his right hand at the bottom - but it's at the top at the first cut. (00:25:20)
Continuity mistake: The decoration in Aunt May's glass during the chat about Humphrey's Marvellous Magic Show changes position between shots. (00:19:35)
Continuity mistake: At the botanical gardens, DS Florence Cassel is showing the photo of the deceased to other visitors. In close-up, she lowers the left hand with the notepad, but she has that hand up in the faraway shot that follows. (00:12:45)
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 ★