Deliberate mistake: Jim was sitting on a bench along the road and Amy [Brie Larson] walked by (several feet away), apparently not noticing him. (Jim was seated between other people.) Brie got into her car and adjusted the rearview mirror, catching sight of Jim on the bench. A driver would adjust the rearview mirror, if necessary in the first place, to align it with the rear window, not angle it to the right to be able to see the sidewalk. (00:51:34 - 00:51:55)
Deliberate mistake: During his autopsy in Saw IV, it is revealed John Kramer was 52 at the time of his death. Kramer's role in this film is the very early stages of his time as Jigsaw, shortly after his cancer diagnosis, which would put him in his early 50's. However, he looks far too old to convincingly be that young (Tobin Bell was in his mid-70's at the time of filming). He even looks older than he did when he was on his deathbed in Saw III.
Deliberate mistake: Frequently during the movie, British surgeons are referred to as "Doctor". In Britain, surgeons are always referred to as "Mister"; this is a hold-over from the surgeon's non-medical past (barbers, etc). This would likely be confusing to American audiences.
Deliberate mistake: Where are the motorcades for the other world leaders?
Deliberate mistake: Poirot riles up Pennington narrating the story of Grand vizier Ptahhotep who was crushed under the weight of the silver he embezzled. It's a lovely moral story, but Ptahhotep was actually a virtuous administrator and is credited (with various caveats) with writing "The Maxims of Ptahhotep", one of the first books in human history, and there's no record of such a story. It's likely that Poirot made that part of the story up counting on Pennington's ignorance on the subject. (00:44:20)
Deliberate mistake: When Batman enters the replica of The Joker's apartment there's no place for The Joker to hide. Yet seconds after Batman enters, The Joker comes out of nowhere to hit him with a pot.
Deliberate mistake: The (fake) confession letter was postmarked from Ohio and sent to Allison Connor, 331 Henry Lane in Hilliard, MB 21243. No U.S. state has a postal abbreviation of "MB." The way the "B" was written in thick bold letters made it resemble a "D" - "MD" represents Maryland (where the film apparently takes place). Also, there is no current 21243 zip code in the U.S. There is a 21241 for Baltimore City and the next consecutive zip code is 21244 in Baltimore County. The created address LOOKS real. (00:50:44)
Deliberate mistake: Considering the position of the surveillance camera (height and angle - almost parallel to the side of the building as well as to the sidewalk), plus the lens being indented within the outer frame, it would not have been able to capture a view of Redd on the sidewalk below like it did. (00:24:40)
Deliberate mistake: Kristin would not be physically able to hold Fabrizio from falling over the ledge using only one hand/arm (or even both). (01:30:22)
Deliberate mistake: When Dooley looks at the photo of himself, Jerry Lee and his wife Tracey, it's obviously a still shot from the first movie, as the angle the picture is taken from was obviously not taken by anyone else as they were the only two in the apartment with Jerry Lee at the time. (01:11:40)
Deliberate mistake: When Lithgow is shot in the leg and trips backwards over the crate or box, the stunt man is deliberately visible. It's not Lithgow making the fall.
Deliberate mistake: During the song Adelaide's Lament, Adelaide goes to her medicine cabinet, opens it, and there is a cut to a shot from "inside" the cabinet as she surveys all the medicine she takes to treat her "cold." From the inside, the cabinet is almost twice as wide as it is when it shows her open and later close it from the outside.
Deliberate mistake: During the fight at the Unity Day Festival, at one point Goblin is confronted by some cops and beats them up. Watch closely... you can tell that the first and second shots are just different takes of the same stunt from a different camera angle. Goblin's movies are exactly the same (except slightly faster in the second shot), and you can also tell it's the exact same two cops he's hitting. They tried to artificially lengthen the scene by showing two slightly different takes of the stunt.
Deliberate mistake: Wyatt is killed in a park next to El Prado museum (which can be seen in the background). Then S and McQuarry cross the street and appear next to where the bank was. This speeds the pace of the movie, but truth is that the building of the bank and El Prado are 20 minutes walking distance away from each other.
Deliberate mistake: Declan and Preston are hanging out at an airfield in a blue car when they realise one of the numbers in the notebook they have is an FBI access code that The Jackal now has. In establishing shot of this scene you see the blue car sitting more towards the left with Declan on the hood. Then when Preston calls in this finding and they get a helicopter to come pick them up, in the shot with the chopper coming the car is now suddenly much further to the right. It seems they had to move it during filming to allow a place for the chopper to land. (01:19:05 - 01:20:30)
Deliberate mistake: When Michelle brings up the photo of "Fake Denzel" on her phone, she says she put it into a hidden folder. Problem? She only presses on her phone once (based on the sound you hear), and has the photo up and filling the screen within about one second. Totally preposterous. Obviously, it was done that way to keep the scene moving quickly... but there's no way a single button press and a timespan of about one second is going to bring up and maximize a photo from a hidden folder on her phone.
Suggested correction: The very faint click you hear could be her phone unlocking, so we don't know how often she taps the screen. That said, yes, it's unlikely she'd be able to access the photo that fast.
I don't understand this correction, because it literally just seems to reinforce the original mistake. Unlocking her phone wouldn't instantly bring up a photo in a hidden folder.
Deliberate mistake: One of the first shots in Greece shows Benoit Blanc and Lionel standing on the pier. As director Rian Johnson himself says in an interview for the Vanity Fair Youtube channel, "Matches nothing else in the scene lighting-wise, but it's gorgeous soooo...who cares." (00:13:30)
Deliberate mistake: When Ami's school friend is killed, a short sword is stabbed into the top of her head. Less than a half-second later, we see her face is totally coated in blood, and she gurgles even more blood before dying. There simply has not been enough time for such a volume of blood to have dripped down her face.
Deliberate mistake: When Jenny writes "dick" on Matt's forehead, she does not stop the beam but the word is written with the letters separated.