Revealing mistake: When Shin begins chopping off Jay's head, in the close-up shot a line can be seen around the part of Jay's neck that hasn't been cut yet, revealing that it is a prop head. (01:35:05)
Revealing mistake: She is driving and puts her phone down, you can see that car shifter is in park instead of drive.
Revealing mistake: After successful surgery, Bruce's friend shows him the first page of a newspaper with the headline about the news, "The National Whisper." The 'date' is "November 2016", which is a bit odd (a monthly newspaper?), but even better is the fact that it just sports obvious gibberish all over. The title of the boxed article is "Geiare la goer uoa oge ou osgeou osd ogoernis pgoer aoubepre obieri ai beiragoer." (00:17:15)
Revealing mistake: Ron leans against a barrel and sets in motion a series of events leading to an explosion. For being able to tip it with such a modest push, it is obvious it was empty (confirmed also by how it bounces). (00:02:20)
Revealing mistake: A basket with fireworks catches fire. When the basket is flung into the air, they forgot to add the CGI for it, so it's not burning at all. But the effect is there in the second shot, when Aladdin bicycle kicks it away. (00:06:00)
Revealing mistake: The use of a green screen (or other color) during most of the cafeteria scene is obvious if you watch the people in the background instead of the main characters and is flawed in a few ways (e.g, varying angles, greater distance, continuity of a person, etc). For example there is a man wearing a blue shirt/tan pants and carrying a briefcase walking down the aisle toward the Good Boys' table. When the man is walking along the wall that is behind the Good Boys, he is further ahead than he is when he is picked up again. Also, this man shows up in front of Max when Max is walking to Soren's table. The man also appears walking along the back wall with a woman. Watching the wall behind Thor and Lucas, it is sometimes at an angle and other times looks more distant. Some of the people would essentially be walking "out of the wall" in order to appear where they do (e.g, the boy with a backpack).
Revealing mistake: During the interview, you can see a monitor with the lyrics of "Something", even though he is supposedly improvising.
Suggested correction: This is a deleted scene. It is in the extras on the DVD but it is not part of the movie.
Revealing mistake: When Anita goes to destroy their getaway car you see her pour gasoline all over the roof and hood. Then when she lights it on fire it's only burning inside the car. (01:06:40)
Revealing mistake: The camera holds on a close-up of the article featuring the 'Female President of the Network' Caroline Morton for 3-4 seconds, long enough to allow to quickly browse the text and easily see that it's a generic article about women in workplaces used as filler text and not the interview Katherine is reading. (00:03:25)
Revealing mistake: When the zombie crawls into the hardware store breaking through the bottom part of the barricade, you can already see on the wood plank the line where the wood is supposed to snap in half. (01:05:20)
Revealing mistake: When Shaft thinks about the address of the drug supplier, he stares at a newspaper clipping on the wall. The clipping is zoomed in close for over 1 second, and it's more than enough to spot the famous words "Lorem ipsum..." at the beginning of the article, revealing the clip to be just a movie prop with the industry standard filler text jibberish. (00:27:10)
Revealing mistake: When Tree kills herself by throwing herself out of a plane, in the shot where she lands in front of Carter and Danielle, it's very blatantly obvious she was filmed on a greenscreen and comped in. The lighting on Tree doesn't quite match the lighting of the scene, and there are very obvious and unnatural hard lines around her hair where the background was rotoscoped/keyed out.
Revealing mistake: After breaking Zapan's nose, Alita jumps on the table of two guys and trash talks them into a fight; before they attack, the two bottles of beer on the table are different, one being the generic red and white Cerveza, the other with a peach colored label. When she kicks the CGI bottles, those are two identical Cerveza ones. (01:01:15)