Revealing mistake: When making traps, he's harvesting powder from a spent shell (primer has been struck). (01:05:50)
Revealing mistake: As Liam Neeson looks at the money in the bag, he turns it over and it says "motion picture use only" on it.
Revealing mistake: The jaguar near the start jumps onto the bar and prowls along it. It knocks over one glass with some force, which shatters, but the second glass is barely tapped by its foot and it smashes to bits too, when it should just have been pushed out of the way.
Revealing mistake: When the military security checks Flash's phony badge, the name on the personnel list to the right does not match the fake identity; Barry's false identity is "Rowe, Wesley", but in the list the name "Band, Ryan" is highlighted. This mistake was not present in the theatrical 'Whedon' cut where the name was altered to match. (02:27:05)
Revealing mistake: When Bloodsport rescues Ratcatcher 2 from on top of the car, they don't actually dodge the arm coming for them but are going straight through like it's not even there. (01:54:16)
Revealing mistake: When Venom violently opens the large portal of the church, he barely takes one step but the doors close basically through him. (01:08:15)
Revealing mistake: After Jamie told Scottie, "Dad would have been proud of you", she was shown against a mountain background - but she was in the woods surrounded by trees. (01:06:15)
Revealing mistake: After he takes his plate carrier off which looks suspiciously light, the rest of his armor is air-soft gear meant to stop BB's, not high power 5.56 rounds. (01:43:00 - 01:45:00)
Revealing mistake: During one of the chase scenes, an SUV hits a rock barrier and flips over landing on its top. The car spins around, and we see that it is empty. The driver then climbs out as if he was just in the vehicle.
Revealing mistake: The rear of the steer's carcass was on fire and smoldering, but wasn't seconds later in the aerial view. Also in the aerial view, the position of the steer relative to Alexander was different. (00:06:00)
Revealing mistake: Much of the cemetery scene with the Mentor was "green screened." The backgrounds were inconsistent (e.g, trees and tree trunks) and sometimes the Virtuoso's and Mentor's head were practically together when facing each other. The sizes of their heads also varied at times. The Mentor also was at an angle to the Virtuoso during his long speech, at least giving the impression that he was using cue cards to remember his lines. A couple times, the Mentor looked like he lost his place. (00:15:24)
Revealing mistake: While Martin is being mauled on the ground by Valentine the zombie tiger, he is being thrown up and down and side to side. There are a few seconds where the tiger takes a small break and watches him try to crawl away, but his body is still swaying around as if he still being grabbed by the tiger, but the tiger is not touching him; they did not match the animations of the tiger with the physical acting of the actor properly.
Revealing mistake: The "bridge" within the crime scene tape is obviously a prop. It should be a continuation of the road, but it is tilted to the left and is more vertical (around 45°). The bridge isn't even very high. When Byron and others go under the bridge to look at the dead girl, there is only a few feet above their heads (clearance under the bridge). (00:04:54)
Revealing mistake: When Teddy's Cadillac Seville is blown up, you can see that the engine, transmission and catalytic converter have all been removed.
Revealing mistake: During the attack on Druig's village, there's a shot of Gilgamesh and Thena running towards the camera, then stopping as two Deviants fly over them. During this scene, you can see Don Lee (Gilgamesh) briefly look straight at the camera (he's not looking at either the village or the Deviants, since they headed in the opposite direction). (01:13:50)
Revealing mistake: It was "raining" when Francesca was driving toward the house, but her vehicle "moved out of the rain" before coming to a stop. Furthermore, when the camera returned to Francesca walking toward the house, it was not raining and the driveway did not look wet. (00:48:53)