Continuity mistake: In the scene where Bette Davis has lost her shawl there is a shot of her and Maggie Smith from far away. They talk about the time and in the background Angela Lansbury is drinking. She puts down her glass and leans her head on her hand. Then the shot changes to a close-up of Bette Davis and Maggie Smith and you can see Angela Lansbury in the background, with the glass in her hand, just about to take a drink. (00:55:05)
Visible crew/equipment: In the scene near the start of the movie when Lois Chiles is showing Mia Farrow her bathroom and Mia Farrow is saying "Yes, It's lovely," on the mirror on the right you can see a member of the crew crawling around on his hands and knees. This is visible on the DVD as well as at the cinema. (00:05:50)
Plot hole: According to the denouement sequence shown in the film, Linnet Ridgeway is shot asleep in her bed approximately three minutes after retreating from the lounge. Less than 2.5 minutes pass from the moment Linnet leaves the lounge to the moment when Doyle is left alone by the other guests. It takes another 30 to 45 seconds for him to pick up the pistol, rush into his cabin and kill his sleeping wife. How could Linnet have walked to her cabin, taken off her jewelry, changed into her night-dress, retired to bed, and fallen asleep in 180 seconds? (00:59:00)
Suggested correction: The sequence never showed when Linnet goes to sleep. We can't be sure how long it is between her leaving and Simon shooting. All we know is in the actual scene she leaves after having already taken a sleeping pill. This is "movie time", not real time. 3 mins can be 30 mins in movie time. The flashback sequence doesn't clarify anything based on her timeline.
This...is not at all what happens. This is the 1978 movie; Linnet is playing cards with the others up until a moment before cutting the game short not by her choice but because of Jackie's interference, so certainly took no pill in advance nor does she take one on screen, and the characters interact with no interruption from that point on leaving no room for an implied 'movie time' elapsing at a significantly slower rate than 'real' time.
Factual error: After Linnet Ridgeway had almost been crushed by a stone falling down from the temple of Karnak, Dr. Bessner advised her to go back to the boat to have a rest. She replied that it can be for just a couple of hours, as she must see the temple of Abu Simbel in the evening. In the next scene, she is really visiting Abu Simbel together with Simon and in the late evening they are back on the Nile steamer. This is absolutely impossible, as the distance between the temple of Karnak and the temple of Abu Simbel is about 400km (250 miles). By that time, it would have been impossible to manage 800km (500 miles) within one afternoon just for a visiting tour. And it is not very logical, as the Nile steamer was going up the Nile to Wadi Halfa, so they would have passed Abu Simbel anyway later during their trip. (00:47:00)
Factual error: In the Abu Simbel scene, watch closely when they show a side-view shot of Jackie, accidentally depicting the shores of Lake Nasser in the background. This reservoir was built only in the 1960s and didn't exist at the time the movie is set in (1930s). (In fact, the whole temple had to be cut from the rock and moved to higher ground following the completion of the Aswan Dam, so the "original location" was no more available for the film crew.) (00:51:15)
Plot hole: Simon wasn't shot at the time everyone thinks - he shoots himself after killing his wife - so how did he get all that sweat, in his forehead, through his hair? It was all over him.
Suggested correction: He'd just been running around the boat, and he'd just killed his wife. That'd make anyone sweat.
What the OP says is that he's already sweaty before he does any of that; if you look at the first scene when he's tricking the others, and in Poirot's flashback during the denouement, it is true that the actor's face is already pretty sweaty, although not quite as much as it is later when Simon is actually in pain. Look at him when he closes the bottle of varnish, his hair is a mess sticking to his forehead. You could argue he was nervous, but in the rest of the movie he keeps his cool all the time without such displays of perspiration.
Continuity mistake: Take a look at the Karnak temple scene when the massive stone block is pushed off the column to kill Linnet. Seconds before the stone falls, the column and parts of the floor beneath are brightly lit by the sun. Also notice that the stone is positioned maybe 2 yards off to the right of the column's centre. When the stone is coming down in the next shot, most of the column (and the ground) is suddenly in the shade. And when the stone hits the ground it is no longer positioned to the right of the column but in front of it. (00:47:40)
Factual error: The body of Louise (the maid) is discovered when the room-service guy drops a towel on the floor and it lands in a pool of blood. The blood obviously ran out of her cabin from under the closed door. However, the cabin door thresholds are not at level with the floor (neither outside nor inside the cabins), but several inch higher, so her blood could not possibly have escaped through the cabin door. All along the movie you can see the actors carefully stepping over those irritating thresholds in order not to stumble, though I think it is hard to spot the edge from within Louise's cabin. But watch when Dr Bessner enters her cabin to investigate the body, it's pretty obvious he takes a step "down". (01:45:15)
Suggested correction: You're right, there are big thresholds. But I have just watched this film again, and when Poirot and Race enter her room after she is discovered, you can see vents in the threshold, which would explain how the blood seeped out onto the deck. I do think they were put into the film set for the room interior shot on purpose to explain how the blood seeped out, as I cannot see any vents when glimpsing the thresholds on the deck side.
Continuity mistake: At the end, when people leave the boat, as seen in the wide shot, the wood plank is at a different distance from the stair's handrail than when Rosalie Otterbourne and Ferguson leave the boat.
Continuity mistake: When Poirot calls the doctor's testimony "irrelevant", the doctor's left hand is on his leg, but he's holding his clock's chain in the next shot. (02:00:25)
Continuity mistake: When Poirot says "That's not quite right" in rebuttal to Race's frustration, he raises his index finger. The same gesture in the reverse angle has him with both index and middle finger raised. (01:46:10)
Continuity mistake: Poirot has a chat with Jackie before dinner after the murder. She says she is ashamed, holding the railing. Poirot tells her that now he, Simon, is available to her again, and Mia Farrow has just the back of her fingers against the railing. (01:40:45)
Continuity mistake: Inside Pennington's cabin, Poirot finds the document they were looking. He shows it briefly to Race, who is holding a file with a black binding on the right side (so he's holding it the wrong way). George Kennedy shows up in the next shot, and Race is standing there holding the file this time the correct way, and facing the other way after a further cut. (01:38:05)
Continuity mistake: When Poirot accuses madame Otterbourne repeating the "can't libel the dead" phrase, Angela Lansbury is staring him down with her left hand nowhere in sight. Reverse angle, and she is clutching her pearls with that hand. (01:35:05)
Continuity mistake: When Mrs. Van Schuyler mentions a "popping sound", David Niven's position is different in the two takes; first his hands touch, then he suddenly has one hand on the armrest. Similarly, when she mentions "an indifferent champagne" her hand is on her embroidery, but she was gesticulating away from it before the cut. It's then Peter Ustinov's turn to be inconsistent; Niven asks "Could it have been a small pistol" etc. and Ustinov is fingering his moustache, but in the next shot he isn't. (01:29:00)
Continuity mistake: Race hears Poirot's morse code and grabs his mighty swordstick; look at his tie. When he's inside Poirot's room, his Royal Green Jackets tie is styled different; in his own room the small end reach approximately the second-to-last red diagonal stripe of the wide part, while in Poirot's room the small end reaches barely the third-to-last stripe. (01:26:40 - 01:27:15)
Continuity mistake: Poirot watches Jackie leave the hotel seemingly falling for Simon's ruse. He's having breakfast; when he puts the croissant in his coffee, the hand holds the brioche with its flat side upwards. Ustinov in close-up is eating the brioche with the curved side up. (00:27:00)
Continuity mistake: When madame Otterbourne says hi from her natural element (the bar), David Niven pokes his head in behind Ustinov's, but in the next shot he's not leaning in, he's more like standing behind him, straight. (01:34:00)
Continuity mistake: When Colonel Race comes to Poirot's rescue, Poirot's arm is outstretched and stays that way even after a reaction close-up on Peter Ustinov with his arm lowered, as you can tell by the part of his arm in frame. (01:26:55)
Continuity mistake: When Race and Poirot lift Simon Doyle from the bed, he helps himself up using Peter Ustinov's arm in the first shot, David Niven's in the second. (01:20:05)
