Continuity mistake: Interviews at the American Colony Hotel in Jerusalem. At quarter to 4 Lennox fixes his mother's wristwatch; the sunlight is much dimmed down in the shot when she waves him off. (01:00:25)
Continuity mistake: When Poirot sits down with Nadine Boynton, her hat is in a different position on the table in each shot - just look at the flower. (01:01:50)
Continuity mistake: When Poirot takes notes during Carrie Fisher's interview, his panama hat is at a different angle in the close-up of his writing hand than it is in the wider angle. (01:02:05)
Continuity mistake: Poirot is at the hotel's reception, phone in hand, and spots Cope trying to leave. The whole counter in front of Poirot shows direct sunlight on it, but in the conversation the light of the set is entirely different and most of the counter except a couple of narrow spots is in the shade. (01:03:55)
Continuity mistake: Poirot and colonel Carbury are going up a flight of stairs when the Belgian poses to his positively baffled friend a few questions. Before the camera cuts the first time, Carbury takes in his right hand the baton he was carrying under the left armpit, but in the next shot it's back exactly where it was. (01:06:10)
Continuity mistake: When Poirot leaves Carbury to go question the two remaining Boyntons, the military vehicle he gets on has a different serial number than the one he steps out from. (01:07:15)
Continuity mistake: Poirot confronts Carol inside the cave. When she says that "In the morning the whole thing seemed ridiculous" there's a quick reaction shot on Ustinov, and the bottom strap connected to the glasses tucked inside his breast pocket runs a few inches above his waistcoat, across the shirt; in the rest of the conversation it practically touches the waistcoat. (01:09:05)
Continuity mistake: In the cave, Raymond turns his back to Poirot casually saying that his mother was "pretty upset." Notice the sweater he threw on over the shoulder. Cut to a couple seconds-long flashback with his mom hilariously overreacting, and when we see him again the sweater is on his shoulder in a completely different way, as you can see from the decorations. (01:09:55)
Other mistake: The spider scene is wildly different when Poirot narrates it at the dinner table (Miss Quinton immediately replies "Oh yes, spiders don't frighten me") compared to the actual scene (she said that replying to a different line). (01:12:20 - 01:33:40)
Factual error: When Poirot sets his trap about the "brown spider", the man next to Lady Westholme is intently reading an issue of Pic magazine; it's the July 1938 issue with Carol Landis on the cover. But the movie is set in May 1937. (01:12:30)
Continuity mistake: After the spider scene, colonel Carbury and a certain Captain Rogers (not that one) approach Poirot; suddenly at the entrance behind them there are people who weren't there a moment before. (01:12:35)
Continuity mistake: Carbury brings Poirot the report with the results of the questioning of the various "Arab boys." Poirot sets it on the counter of the hotel's bar. The colonel does not touch it until later, when he does it's turned differently. (01:13:00 - 01:13:25)
Continuity mistake: Colonel Carbury is getting a tongue-lashing from Lady Westholme. He picks the cup of tea from his attendant, with the right hand, and the receiver is on his left hand. Camera cuts away for one second on Lauren Bacall, and then in close-up the colonel is holding the phone with his right hand, immediately switching to the left. (01:14:25)
Continuity mistake: On the final day of the mystery, Doctor King apologizes to Poirot at the concierge. Poirot's reading glasses are located in his pocket, towards the left or center, as we can tell by the straps. When the two are coming out of the hotel, the glasses shifted to the right corner of the pocket. (01:14:40)
Continuity mistake: With Dr. King at his side, Poirot waves hi to Hassan, the 'Arab boy'. The position of Poirot's hat and cane is different in the two shots; in front of him, or down his left hip. (01:14:55)
Audio problem: Hassan runs away, chased by Dr. King. A wild Lady Westholme appears and says a line that does not match her lips. (Peter Ustinov's lips move without a sound as well, but in his case Poirot is self-censoring an expletive). (01:15:15)
Plot hole: Dr. King is chasing Hassan through the market. She runs after him at great speed; even assuming that they could have run in a circle for a while, it makes no sense (especially given her role in the plot) that Lady Westholme is one of the people in the market crowd, casually chatting with a merchant, when she was behind Poirot, at the hotel, as the chase started. (01:15:45)
Plot hole: The movie at best is being dishonest with the ending of the chase scene; to keep Dr. King as a possible suspect, the gunshot happens so shortly after she went out of frame (with no cuts) that (since she is -NOT - the killer) there is no possible way that the gun could have ended in her hand. There's also no possible way for the culprit to escape, to find Hassan in the crowd and be there at the perfect moment, etc. (01:16:35)
Continuity mistake: When Dr. King drops the gun, in close-up it bounces on the back of the thigh of the victim, but in the previous shot she tossed it nowhere near that spot. (01:16:55)
Continuity mistake: One of the menacing individuals behind Dr. King is wearing a keffiyeh that obscures his face entirely. The loose part down his chest is in a different position in the widest shot when they back her against the wall. (01:17:05)
