Revealing mistake: When making traps, he's harvesting powder from a spent shell (primer has been struck). (01:05:50)
Revealing mistake: When Finney is looking for the bike lock's combination written on the wall, the distance between the mattress and that wall (several feet) can be seen. However, the next time Finney wakes up on the mattress, the mattress is against or almost touching the corner, but the mattress was not that close to the adjacent wall. Furthermore, when the Black Phone rings, the mattress is the same distance from the phone as it originally was (which would be several feet away from the wall). (01:04:59 - 01:10:53)
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: Deacon uses "hidden" food to get the dog to come up to him. The "treat" is largely concealed - but the dog's slobber gives it away. The camera shifts after Deacon's hand goes next to the dog's mouth, giving the impression that Deacon is just petting the dog under his neck. (00:06:35)
Suggested correction: He was feeding him. You can see him eating out of his hand. The food isn't "hidden" You can hear the dog sounding as if he were eating something and his face is in his hand. Those were added sound effects in post. At first glance I got the impression he was giving the dog a treat as they were pals.
Part 1: Based on the circumstances plus Deacon's actions immediately before, during, and after his encounter with the dog, I believe it was a lousy attempt at luring the dog but trying to give the impression there was no lure (food). Deacon did not have food when he came out of his house and wasn't expecting the dog to be there. Deacon even pointed his right fingers toward the dog when he said, " You [are] the one [who has] been gone for the last two weeks." Deacon stoops down and [continued].
Part 2:...makes an effort to point his right hand fingers downward, again giving the impression he wasn't holding anything (food). If feeding a hungry, cautious dog, I think he would have displayed the food in the palm of his hand (what is there to hide if actually feeding the dog?). When "sneaking" the food into the dog's mouth, a small piece can be seen falling to the ground. Deacon holds the dog under his neck, probably to keep the dog from reaching the food that has fallen.
Part 3: (The dog later picks up the piece that fell.) Taking all these odd movements into consideration, I'm sticking with my assertion - Deacon "surreptiously" lured the dog, but his actions were noticeable, thereby revealing what was actually happening. Also, if the dog was missing for two weeks, Deacon would not have been likely to bring food out for the dog that morning. Anyone wanting to view the scene and serve as a tie-breaker, start at 00:06:26, watch Deacon's right fingers @ 0:06:32+.
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 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: At first glance, the cow at the start may have looked real, but its limited mouth movement while eating grass (without any grass being pulled out) indicates it was a mechanical cow. The cow also did not move its rear end or raise its head when Fenn and Geary approached and stood right behind it. A real cow would not stay in the exact same position (motionless) that amount of time. The cow's "fur" also did not look real. (00:02:50 - 00:03:24)
Revealing mistake: The blemish/mole that was on the right side of Ghost's nose showed up on her left side (and she was not looking into a mirror). (00:57:40)
Revealing mistake: As Liam Neeson looks at the money in the bag he turns it over and it says "for motion Picture use only" on it.
Revealing mistake: Some views of Malik driving show him, as well as Jay in the back seat, on the opposite side of the car (mirror image). (00:36:55)
Revealing mistake: When Paul and his father Leto are walking through the field between storage bins/sheds, the sheds are largely situated perpendicular to their path. After they stop walking, the angle of the shed behind them shifts to being roughly horizontal to their path. A front shot of Paul still shows a shed on the opposite side as being perpendicular. The background also changes to blurred, still images of dried grass (with no light breeze). (00:14:09 - 00:14:43)
Revealing mistake: At Mrs. (Louise) Bundy's house, Ressler and McChesney were seated at the coffee table, maybe 3' apart. When Louise was sitting in the chair talking to them, only some hair to represent McChesney was on the left side of the screen and Ressler was not visible. It was obvious Louise was delivering her lines without the two sitting there because her head and eyes were turned way too far to the left and right (beyond where their bodies would have been) to be making eye contact with them. (00:45:25 - 00:46:34)
Revealing mistake: Right after baby Estella is born there is no umbilical cord.
Revealing mistake: The way in which the flame from the fallen candle started burning the wall painting of the family, as well as how the fire spread (rather, didn't spread) and looked, reveal the fire was computer-generated, not real. (00:24:23)
Revealing mistake: There's no doubt that Joey and his mother were not real kangaroos, but there wasn't even an attempt to make them look at least semi-real with animatronics or better CGI. The kangaroos' appearances were more along the line of what would be expected in a cartoon or all-animated movie. (00:01:00)
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: The Giles brother who got "hung" when he fell after getting shot by MacMasters can be seen moving his body (mostly arms). (00:04:06)
Revealing mistake: Each time Julia lifted the roof window on the camper, it was flush with the roof (like a sun or moon roof). However, two individual shots of that area showed a raised section about a foot high with two windows on one side - totally different from the flat roof window. An aerial view of the roof did not indicate that these were in different areas of the roof. (00:52:20 - 00:55:03)
Revealing mistake: DEA Agent Rick Bowden was already seated "in the best position" before knowing where Ross would sit in the SF library. Chris Tarbell already had a surveillance camera behind the seat Ross chose, giving him a clear view of Ross, also before knowing where Ross was going to sit. Even if there were cameras in other positions, the DEA Agent and Chris Tarbell being at the right spots in advance was too coincidental to be by chance alone. (00:02:09 - 00:02:30)
Revealing mistake: When the McDonald's bag could be seen setting on the desk, it was about as high as Slahi's chest. When there was an angled view of Slahi from the chest up, the McDonald's bag was as high as his neck (and, obviously, not setting directly on the table). (00:20:20 - 00:21:23)