Episode #1.5 - S1-E5
Other mistake: An enraged Richard tries to get the drawing board in position making a bit of a ruckus. If you look at the board, it has names and pictures on it; they are from the future, since they are part of the 6th episode, "An Unhelpful Aid", evidently filmed earlier, out of order. (00:07:25)
Episode #1.5 - S1-E5
Plot hole: Leon Hamilton is the most hated man in Sainte Marie, with over 900 people on the island conned by him. Yet exactly one person in the whole island knows how he looks like, every newspaper and website never ever published a picture of him even during the very public trial when they were trying to get their thousands of dollars back nor publish an archive picture after his death.
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)
In the Footsteps of a Killer - S6-E7
Trivia: In the close-up of the diary of Julie Matlock, you can read in the column to the right of the page with the mysterious number 19871 a name; Agnes Dahan. It's the name of the production buyer of the episode, and long time staff member of the show in production and art department. (00:20:20)
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.