Episode #4.8 - S4-E8
Continuity mistake: After the chat with the Commissioner, Humphrey gets infodumped on by his team. Dwayne passes him the insurance documents, then JP speaks about the personal effects of the deceased, just as Goodman split the papers given by Dwayne one per hand. Reverse shot and they are back one stacked on top of the other. Back to the previous angle, and they are divided again. And so on. (00:25:10)
Episode #4.8 - S4-E8
Continuity mistake: Dinner with the father, part 2. Humphrey is having trouble speaking, and his dad asks "Are you like this at work?" During that shot you can partially see that Mr. Martin Goodman QC is holding the glass of wine, while he's holding a fork in the previous and following. (00:29:25)
Episode #4.8 - S4-E8
Continuity mistake: When Humphrey is done with the murderer, he walks back to the stand, with Florence fawning over his performance. In the longshot Commissioner Selwyn Patterson 's arm is in the shadow, in the closer angle the shadow goes to half his pec too. (00:47:30)
Episode #4.8 - S4-E8
Plot hole: The way the murder happened (where was the gun shot from?) is entirely unknown for the first couple of days, not even a hint - it seems the investigators don't care at all about it, which is quite silly per se. More importantly though, knowing so little about the way the shooting happened would have at the very least prompted an analysis of the shirt to check the entry wound and any residual. During that sort of test the 'other substance' used in the trick would have been easily discovered (visually it is radically different up close and drying out), exposing the culprit.
Continuity mistake: Laura Hagen is back in the cabin to retrieve the sample bag she forgot. The bag was under a map on the table, which she moves by a whole lot...or just a tiny bit, when the table is shown from another angle. (00:02:25)
Continuity mistake: Humphrey and Florence go back on the boat after the preliminary interview. Florence is on the phone with the Coast guard when she gets on the boat; the phone is on her left hand, and the right hand is occupied by the notepad. When she tells Humphrey the coast guard's report, they have traded places. (00:09:20)
Continuity mistake: Dwayne mentions enlisting the help of the Saint Marie diving school. At the following cut, his shirt is more open, revealing more of his trademark tank, and he is holding the notepad where it would have been visible in the close-up. (00:09:55)
Other mistake: Commissioner Selwyn Patterson puts some pressure on Humphrey and the team saying that "a wealthy tourist has just been killed." But Dan Hagen was not a tourist; he lived on Saint Marie with his wife, as said by the fellow oceanographer Jonathan Taylor, and they have a villa. Someone as well connected and nosy as Patterson wouldn't miss the notion of a multimillionaire living on the island. He also says that he needs to reassure the yacht club that there are no pirates in the area, but it was already established by the coast guard that no ships approached the area. (00:12:15)
Character mistake: The rap sheet of Laura Hagen's dad says that he served "half of an 12 years sentence." An twelve? (00:15:50)
Continuity mistake: Dwayne points his finger at JP telling him his former superior said "a policeman can't have any weaknesses." Reverse shot, and Dwayne's hand is nowhere in sight, but it is a moment later. (00:16:30)
Other mistake: It's played as a gag, but still it's quite inconceivable that in "fifteen minutes" it would get pitch dark so that Dwayne can avoid his duties sanding the ship! How much time could he have bought even if he had more excuses up his sleeve? Goodman really can't tell the difference between 15 minutes and a couple of hours? The scene started when it was nowhere near dawn. (00:21:10)
Continuity mistake: On the derelict boat, Humphrey invites Dwayne to do some sanding together, but Dwayne has a counterproposal. Humphrey listens to it with his hand on his hip, away, on the hip again. (00:21:15)
Factual error: The website of the toy manufacturer has as address for its store a location in Harrogate, but the ZIP code has an incorrect format, with the 4th character being an O and not a zero, and HG4 being the neighbouring Ripon. (00:28:30)
Continuity mistake: Early morning at the station. Florence just arrived, and Humphrey is telling her about his suspicions on Nicky Hoskins. She replies that she needed the job; between shots there's an obvious difference in the positions she listens in. She is palm to back at first, then both palms upturned. (00:36:50)
Continuity mistake: Humphrey, triumphant for the discover made through his gossip with the roomie of the suspect, slams the yachting magazine on the desk with a swift motion of his right arm, which is the left arm in the next shot. (00:37:25)
Character mistake: Humphrey tells the riddle of the two barbers wrong; you have to set it up saying that the 'good' barber has a great haircut, not that he's great at cutting hair, or you negate its point (which is that the 'bad' barber with the bad haircut is the one who did the haircut to the good-looking barber, and vice-versa).
Continuity mistake: During the opening party, extras are recycled - in particular, a man with a white fedora appears multiple times, sometimes with shades, other times not. (00:02:00)
Continuity mistake: Commissioner Selwyn Patterson holds the glass and bottle at a different height in the wider shots (fingers are at the champagne level in the glass) and in close-ups (glass about an inch fuller). (00:03:50)
Continuity mistake: During the rendition of the Commissioner's movements with the glasses, he says in a faraway shot that the governor "was standing with Andy Hammond." Before it cuts away from this shot, you can see JP handing the appropriate photo to Goodman seconds before it actually happens. (00:09:50)
Continuity mistake: Humphrey writes the various names on his whiteboard. In the close-ups that immediately follow (and in those later in the episode, but days have passed meanwhile so it's more understandable) the letters have partially faded. (00:14:15)
Answer: Most likely they had only tropical exotic drinks, he wanted an old fashioned English beer.