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: 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: The fish they were catching were already dead.
Revealing mistake: When Alana is walking toward the students, the hedges are mostly dark green, sheared level across the top, and reach to her elbows. Later (after Gary tells Alana he will take a mirror), the hedges turn mostly yellow and flower-like across the top, are quite uneven, and are as high as her shoulders in spots. (Use of a green screen is apparent). (00:00:40 - 00:01:26)
Suggested correction: One look at the scene make it apparent this entry is totally incorrect. The bushes look natural. The yellowness is just colour grading. There is no sign of green screen usage whatsoever. It would make no sense for this film, especially if you realise that director PT Anderson is known to be very much against the use of any sort of VFX or green screening.
Revealing mistake: Sledding down the hill, the "kid" noticed the upcoming cliff, but an aerial view of the "kid" lying in the snow after he rolled off his sled did not show a distinct cliff/ledge, just a snow embankment (piled - or plowed! - against trees/brush). (00:02:48)
Revealing mistake: Ronnie is shown looking through the vertical-rectangular window of a brown door to Joey's hospital room. His eyes are angled to his left, indicating he is looking toward the person in bed to the left of a double room. When Ronnie is standing next to and facing the man in that bed, there's no door with a window behind him that he could have been looking through. There is a windowless white door on an adjacent wall. (00:00:40 - 00:03:42)
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)
Revealing mistake: Lower-third shots of the aquarium in the background at the Delaware Raceway's sports lounge were often blurred and did not look like they matched full views of the aquarium. (00:36:05 - 00:36:34)
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: After Charlie talks to Emma in Francine's old bedroom and is standing in the doorway, the background (segment of the hallway) is obviously fake. Shown are less than five of the top steps on the staircase, only a fraction of the size of real steps. The lower section of the banister is also a reduced size. (01:31:35)
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: The picture on the wall of a younger Mike on a horse shows his groin against the horse's neck right below its ears - obviously photo-edited/photoshopped. (00:04:29)
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)
Revealing mistake: The hubcap on the road that the "Black Saints" boy tramped on was a prop. He stomped on one side of the hubcap in his sock (his shoe had fallen off while running) and the other half that was not under his foot rose into the air. Also, when Harold picked up the hubcap, it was flexible (rubbery) and curved. (00:05:38)
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: When Julie is running around the city whilst all the extras are stood frozen, there is a moment where she is walking next to a small park, before beginning to turn right and run down a road. Once she runs onto the sidewalk after running down the road, two girls can be seen stood on the same sidewalk holding hands. The girl on the right can be seen moving her right hand ever so briefly, even though the extras are all supposed to be standing completely still. (00:54:35)
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: The "movie set" steps were so steep they almost looked like they were flat against the wall and the handrail posts were so close together they looked more like vertical blinds. The little dog was able to scale the steps one-by-one, but the larger dog had to leap with effort to get to the top. Also, the baseboards on perpendicular walls (lower right-hand corner of the screen) were not in alignment (off by at least 1"). (01:11:54)