Continuity mistake: As the camera is panned wide with an aerial view of the estate there are no leaves on any of the trees. But as Marta steps out of her car, the trees are full of very colorful leaves.
Audio problem: After Harlan knocks over the Go board, Marta says "I'm done with you." When she says that, which is when she puts the two vials on the table, her mouth isn't moving.
Continuity mistake: When they are inspecting the outside of the house, one of the dogs brings to Marta the piece of trellis she broke. She holds it in close-up with the loop facing upwards, but as it cuts to Blanc shouting "Sweet beans!" the circle is pointing down. (00:59:00)
Continuity mistake: Blanc is questioning the security person of the estate. In the close-up you can see him pin a picture to the board using one of the magnets. To the right there's a banana magnet. The tip of the banana on the bottom touches exactly the border of the picture almost in the corner, but in the wider angle we see the photo continues half an inch lower. (00:55:00)
Continuity mistake: Marta tries the back door of the apartment and stumbles upon Walt. When they talk, she fiddles nervously with her mail and brings up an unmarked envelope, which should be on top of everything since she just dug for it. When she retreats into the kitchen, she puts the mail pile on the table; in the first shot there's a bunch of business cards on top of everything; after a view of her face and upper body when she is not messing further with the letters, there's a close-up of her going through the mail, and the unmarked envelope is exactly on top, with the cards gone. (01:26:10 - 01:28:15)
Continuity mistake: After the reading of the will, the family storms the lawyer. Linda is reading the will holding it in both hands, which becomes one hand at the cut. (01:10:25)
Continuity mistake: Blanc says he has no idea how Fran got hold of the toxicology report; in that shot, wide angle, Marta's hair cover her right side of the collar of her coat, like in most of the scene. But in the close-up that follows, when she blurts out of the reason, her hair is on the inside of it. (01:54:10)
Continuity mistake: During the explanation of the events, Ransom angrily replies to Blanc "You have her confession" as he objects that there's no proof about the vial switch. Daniel Craig says "All right, yeah" arms down, but in the next shot he is shown at the edge of the frame during Marta's closeup, and his arm is bent. During that close-up Ana de Armas ' hair is also differently spread over the shoulders compared to the following view. (01:52:10)
Continuity mistake: Ransom is brought back in the room for Blanc's denouement by Officer Wagner. First shot he has his hand under Ransom's armpit. Second, Chris Evans' arm is close to the body, no officer hand in sight. Third like the first, hand under armpit. Fourth, the officer is a few steps away and with his arm lowered. (01:46:20)
Continuity mistake: Ransom's presence has been incendiary, and everyone is arguing. Walt and Richard get into a slapfest pawing at each other, and Ransom in a close-up says "We gotta do this more often", eating the biscuit. At the cut with Linda shouting "Hey!" and shutting everybody up, Ransom is in the background just contemplating the cookie still in his hand. Similarly, later when Jacob says what he heard and everyone looks at him, he is chewing in the background, but puts his cookie in his mouth in the close-up. (01:02:35)
Continuity mistake: Marta goes to Ransom to tell him about the blackmail letter. During the scene, the position of Chris Evans' hands is inconsistent between shots (he suddenly has his hand under his chin in just a close-up, and he is holding the letter at a different angle when he tells Marta that the toxicity report will shot the overdose). (01:28:50)
Continuity mistake: At the end of the car chase, Marta is looking at Blanc shielding her eyes with her hand. When he says "I don't know what he came back to do" etc, Marta's hand is off her forehead, but is on in the shots before and after. (01:34:05)
Continuity mistake: When Ransom asks "Fran's alive?" to Blanc, Chris Evans has his hand raised, thumb before his lips. But the hand is lowered in the shots before and after. Similar situation when the word "Jail" is used a few seconds later. Hand visible in close-up, not matching the wider angles. (01:58:10)
Continuity mistake: At the beginning of the movie, Marta is sitting at the kitchen table with her mom while her sister watches crime drama. The arm position of her mom keeps changing during the scene. When she says "Turn it off NOW" she has her elbow on the table leaning on, and then lowers it, still keeping it on the table. In the shots before and after both her arms are off the table. (00:03:00)
Continuity mistake: When the detective (Benoit) asks Marta to be her "Watson", the wind is blowing hard enough to move their hair. In the reverse shot, it is calm.
Revealing mistake: The detectives start interviewing Linda and tell her they will be recording it. The detective pulls out a phone, and we see it recording. He starts talking and the waveform is moving but doesn't match when he speaks. If it were accurate we would see a peak when he talks.
Continuity mistake: Marta picks up the phone at the beginning of the movie. In close-up she is holding it with her left hand, but at the cut it switches to her right hand. (00:03:20)
Continuity mistake: When Ana runs out of the gates in the back yard they're left open, but when Ransom returns at 3 am they're closed. And even though it hasn't rained for a week it is still muddy.
Chosen answer: She is holding cake all 3 times, actually, so the only difference is that the first time she speaks. It can be a case of unreliable narrator, but I'd write it down as a mistake (deliberate, probably, as the phrase is important for the plot and they didn't want to hammer it in), since as you said, the other times even when they tell things to the police in a different way from what happened, the details tend to stay consistent, except for parts that are obviously made up, such as who is putting down the birthday cake for Harlan Thrombey therefore appearing subservient and not as close (when Richard tells the story, it's Walt and his wife, when Walt tells the story it is Richard and his wife).
Sammo ★