Deliberate mistake: Florence and Humphrey set up the scene using a printer that is nothing short of magical; the photos, in color, come out from the machine the instant that Florence displays the profile on screen. It is obviously done to speed up the scene - however, Florence could have printed the pictures beforehand and hand them to Humphrey one by one as she reviews on screen the profiles, there was no need to have them come out fresh from the printer with that kind of impossibly fast timing. (00:15:00)
Death in Paradise (2011)
1 deliberate mistake in The Impossible Murder - chronological order
Continuity mistake: When Aunt Mary is writing on the whiteboard at the hospital, the word "killed" changes style between shots. (00:31:40)
DI Jack Mooney: Strictly speaking, paradise is a state of mind. You know that, right? I mean, the dung beetle - very different idea of paradise, doesn't he? (00:48:25)
More trivia for Death in Paradise
Question: Why did the cord on the wall phone in the police station change from straight in the early episodes to coiled later?
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 ★
As long as such changes aren't an obvious continuity mistake (e.g. changing multiple times during a day), one can just assume the change happened in-universe as well. Things do get broken or updated occasionally. It adds a bit of realism, in my opinion.