The Mysterious Affair at Styles - S3-E1
Continuity mistake: Poirot is concentrating in London, making a house of cards. When he says "I steady my nerves, that is all", the 6 of hearts can be seen in his right hand, and he sets it as the diagonal piece. Cut to Hastings, and then Poirot supposedly still has the same house in front of him...but it is not. Where the 6 of hearts was, there is now a 6 of spades, and the whole castle is different, with the cards pulled tighter together. Later he rebuilds the house, and he sets horizontally in the close-up a 5 of spades, which turns into the 2 of spades immediately after. (01:19:40)
The Mysterious Affair at Styles - S3-E1
Continuity mistake: The guests of Styles Court manage to get inside the room of Mrs. Inglethorp and talk to her before the second fatal crisis happens. In the first wide shot you can see Hastings peek at Lawrence and then look towards the fireplace, which is an action he'll do in the close-up that follows - Lawrence does not seem to look in the direction Hastings is checking out, at all, but that is actually a nice touch considering the resolution. Moreover, in the second close-up of Hastings looking at him (the one that follows the view of the fireplace), Mary is directly in front of Hastings, you can see her insignia and arm. But instantly she is shown at the cut, creeping along the wall behind Lawrence. (00:29:00)
The Mysterious Affair at Styles - S3-E1
Continuity mistake: At dinner, Alfred Inglethorp asks Hastings what he's going to do after the war. The person to his left is placing a glass on the table. The next cut happens mid-sentence and in that instantaneous timeframe the glass is perfectly still while the wine was still noticeably moving in the previous shot. (00:10:10)
The Mysterious Affair at Styles - S3-E1
Continuity mistake: The coroner asks Mary to tell everyone about the quarrel. Frontal shot of Mr. Wells; he is pointing his hand with the spectacles at a certain height. Reverse shot; the hand is lower, resting on the other hand, and only then he raises it to the same level as it was in the other shot. (00:53:40)
The Mysterious Affair at Styles - S3-E1
Continuity mistake: When Evie Howard leaves the house after the argument with Mrs. Inglethorp, she sits on the sofa explaining what happened to Hastings and the others. She has her hands on top of the purse handles. After a brief cut on Mary saying "oh no", one of the handles is free. (00:16:40)
Continuity mistake: When Miss Lemon announces Mr. Halliday, Poirot has two open letters on his desk, side by side when the camera is positioned behind the desk, which turn into one (probably one on top of the other) when the camera is positioned in front. (00:07:00)
The Million Dollar Bond Robbery - S3-E3
Continuity mistake: In the cabin of Mr. Ridgeway, Poirot approaches the portmanteau. In the close-up the tie covers completely the lock before Poirot pushes it aside with his cane, but in the wider shot part of it was already visible, uncovered. (00:24:25)
Continuity mistake: Hastings and Poirot are talking about the optimist friend. Once Hastings says "It bucketed down", he's holding the newspaper, and it stays pretty firm. Miss Lemon knocks, and the newspaper is now folding at the upper corner. (00:06:45)
The Mysterious Affair at Styles - S3-E1
Continuity mistake: About the burnt will, the lawyer asks the obvious question to John Cavendish "Are you so sure it's a coincidence?" He's holding in his raised left hand a sheet. Next shot and he has both hands down on the desk. (00:48:55)
How Does Your Garden Grow? - S3-E2
Continuity mistake: Once Japp passes him back the seed packet telling him it's empty, Poirot checks it out; in the close-up he's holding the paper in a completely different way (the side instead of the top). (00:11:20)
Wasps' Nest - S3-E5
Continuity mistake: Poirot is examining the photos taken by Hastings at the party. Depending on the camera angle, the pictures and their reciprocal distance change across the whole sequence. (00:15:30 - 00:16:05)
How Does Your Garden Grow? - S3-E2
Continuity mistake: Miss Barrowby pretends to have just then recognized Poirot, she lowers her left hand, but has it up when he nods to her, and he has his matching hand suddenly higher too. (00:09:00)
The Million Dollar Bond Robbery - S3-E3
Continuity mistake: When Poirot receives his platter of buttered brains, the delicacy that makes Hastings queasy is turned a different way in each shot (easy to tell from the asparagus). (00:28:05)
Wasps' Nest - S3-E5
Continuity mistake: Having received Japp's phone call, Poirot puts down the picture of the mysterious man. The photo sits on top of the other pictures in a different spot at the cut. (00:35:35)
The Million Dollar Bond Robbery - S3-E3
Continuity mistake: When Poirot says "I'm sorry" to the culprit, he has the hand on the shoulder of his accomplice. Her hair is on and off that shoulder in a blink. (00:48:35)
The Million Dollar Bond Robbery - S3-E3
Continuity mistake: After Ridgeway puts down his Queens High, his hand is hovering slightly on the table, but at the cut it is arched, fingers pointing on the table. (00:28:55)
The Mysterious Affair at Styles - S3-E1
Continuity mistake: Cynthia is sobbing with Hastings, and he asks her to marry him. The handkerchief in her hand changes position between shots (particularly easy to spot when you look at the black band). (01:13:05)
The Mysterious Affair at Styles - S3-E1
Continuity mistake: After Hastings reminds him of the mantelpiece, Poirot shouts "Mon Dieu!" and pounds the table. The cards scattered on the table differ in disposition between shots when he stands. (01:21:05)
The Mysterious Affair at Styles - S3-E1
Continuity mistake: When Hastings spots Poirot from the window as he arrives for the denouement, his hand is in a different position on the window frame (left or right of the vertical bar). (01:26:55)
The Mysterious Affair at Styles - S3-E1
Continuity mistake: At the hearings, the doctor is on the stand and says "There was no strychnine in it." Mr. Wells closes his fountain pen. But then in the next shot he holds it in his hand. (00:52:40)
