Episode #2.7 - S2-E7
Continuity mistake: When Fidel and Dwayne arrive at the place where Camille and Richard are hiding for the hurricane, they can open the doors without a problem, whereas Camille and Richard had taken great care of locking the doors from the inside.
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.
Continuity mistake: When Aunt Mary is writing on the whiteboard at the hospital, the word "killed" changes style between shots. (00:31:40)
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)
Trivia: A bit of the episode has been cut for the streaming releases; at the end of the scene with Humphrey taking Martha's luggage, he would make a date with her for the next day, to cook dinner for her at 8. This has been eliminated probably because it created timing issues with 8 PM being too well lit (in contrast with the supposed timing of the murder) and the ending takes place at Catherine's for a cute drinking scene anyway. (00:22:50)
DI Jack Mooney: My grandfather told me a story once, about these two wolves fighting inside all of us. And one of them is anger, envy, self-pity, regret. The other one is love, truth, faith, hope, that sort of thing.
And I asked him "which one of the wolves would win?" And do you know what he said?
"The one you feed." (00:18:15)
DI Humphrey Goodman: If I am gonna woo the ladies with my culinary skills, I think I need to invest in a cookery book.
DS Florence Cassell: I don't know. Maybe turning on the oven would be a good start.
DI Humphrey Goodman: Yes. The devil is in the detail. (00:24:50)
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)
Question: Why did the cord on the wall phone in the police station change from straight in the early episodes to coiled later?
Question: When Richard reminisces about England, he talks about going to the pub and having a pint. Yet the whole time he's in Saint Marie, he is never seen to drink alcohol with the rest of the team; only cups of tea. Why?
Answer: Most likely they had only tropical exotic drinks, he wanted an old fashioned English beer.
Question: Why don't they even think of pretending the victim just drunkenly tripped in the kitchen while getting a sandwich, and his sister-in-law reflexively tried to catch him, unfortunately holding a knife? He thought he would live a few more minutes, so he could have backed up the story. Instead, everybody (victim and police) just takes it as given that the stabbing will reveal their relationship.
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.