Revealing mistake: Dave Bautista announces that he has arrived. There's a close-up of the kickstand, and you can actually see scratches on the asphalt from previous takes (spotted also by Rian Johnson himself in his video breakdown of the arrival scene for the Vanity Fair youtube channel). (00:15:10)
Revealing mistake: The French tanks that attack Paul et al. Towards the end of the second act are supposed to be Saint Chamond tanks. There is only one of those left in the world, and it is not on screen: the undercarriage and tracks don't even come close to looking like that of a Saint Chamond, because it's actually a BMP-1 dressed up to look like a Saint Chamond.
Revealing mistake: The views to the right and left of the truck on the road did not flow in the manner expected if they were actually there (as opposed to using a green screen). Also, as soon as a "stop" sign could be seen to the right, the camera shifted to the driver, who kept driving as though the stop sign was not there. The structures to the right of the truck were blue but became white when the camera shifted to a front view (not using a green screen). (00:01:20)
Revealing mistake: The 50 dollar bills that appear in the opening credits all have the same serial number (and you can find online the texture they used with great ease, just like the one for the 20 dollar bills stack). (00:03:45)
Revealing mistake: The front and rear views of the house did not seem to properly fit together. The rear view showed more sections, making the house longer than what the front indicated and had three high chimneys compared to only one from the front. The rear view also showed several trees that would be aligned in front of the house, but the trees did not appear to be situated that way. (00:27:49 - 00:29:52)
Revealing mistake: Christine closed her dead brother's eyes without actually touching them. Christine had an open hand (no cupped palm) with her fingers straight out and together; her pinkie finger touched her brother's nose, meaning her other fingers would have been too far away from his eyes and unable to make contact. (01:11:03)
Revealing mistake: When Danny follows Maria outside, he is in front of a well-lighted wide patio door with side windows and there are numerous decorative lights to his right. Thereafter, close-up views of him talking show only some small red lights to his right; the rest of the screen is black. Wide views continue showing the lit entryway behind him. (00:08:44)
Revealing mistake: A white truck could be seen in Tamra's rear window, following her car at varying distances. After Tamra hit Randall on his bike, the white truck was still there but gone when the camera returned to a front view of Tamra. Use of a green screen - the truck could not have gone past the accident or "disappeared." (00:03:35 - 00:04:10)
Revealing mistake: When Yaz and Nina are fleeing the men, the "car" has no visible structure (window frame/body) on the passenger side where Nina is sitting - it is all open "window". (00:38:00)
Revealing mistake: Luke points a flashlight along the side of the staircase, but no shadows are produced on the wall from the vertical posts. Luke points the flashlight in front of himself and produces his shadow on the wall behind (and the shadow doesn't look like the way he is holding the flashlight). After Luke goes through the entryway aiming his flashlight ahead, a circle of light is behind him. The power is out, so the flashlight is the only light source - except that used for filming in the dark. (01:03:00 - 01:05:25)
Revealing mistake: Initially, there is a little movement that can be seen in the passenger's side mirror on Juan's car, but it is subsequently reduced to still-frame. Also, the driver's side mirror is tilted upward, showing movement, but not in a typical position to enable viewing of vehicles behind the driver. (00:00:55)
Revealing mistake: In the underwater view of the fish, the ice hole is almost perfectly round and the ice appears to be quite thin - nowhere near the several inches Jason and Ben have to chip away to reach water. (00:33:55)
Revealing mistake: Driving home from meeting Gigi, there is an image on the windshield of a blue handicapped parking permit/placard that is supposed to be hung on the rearview mirror, but there is no placard hanging - the permit's image is superimposed on the windshield. The image even briefly appears and reappears. (00:34:05)
Revealing mistake: Obvious use of a "green screen" when Elvis and Dylan are sitting on the steps in the stairwell. The five distinct steps that could be seen behind them become a gray wall and the blue handrail posts to the right of the screen become oddly grouped, appearing to be parallel to the right side of Elvis' shoulder/back. (01:09:00 - 01:09:25)
Revealing mistake: During the (second) bank robbery, the ceiling was frequently unusually close to the top of the robbers' heads (inadequate clearance), indicative of a poorly positioned green screen (or CGI). (00:16:35 - 00:17:00)
Revealing mistake: The cell bars appear to be about 4" apart, but are much wider to accommodate the width of The Artist's face/head when there's a close-up of him next to the bars. (01:13:50 - 01:15:09)
Revealing mistake: The aerial view showed it was not raining during the "supercar race", but the ground views showed at least two cars getting sprinkled on (one enough to turn on the wipers). When the camera shifted to road-level, the cars and road were dry. (Suggests filming at different times). (00:31:15 - 00:31:48)
Revealing mistake: When the boulder rolling down the hill hit the man, he "vanished" - he was not flung into the air and it did not look like he got run over by the boulder. [Poor/ineffective CGI]. (00:31:55)
Revealing mistake: The front view of the pirates in the golf cart with Darcy and Tom does not show the driver turning the steering wheel at all, which would mean the road was straight, but the when the road becomes visible again, it is diagonally behind the golf cart. (00:36:45)
Revealing mistake: There are noticeable differences in the appearance/condition of the lattice panels on the deck (overlapping; whether there are missing/broken slats and, if so, their locations), but pinpointing most of the differences would require pausing. When Thomas was seated in front of the panel adjacent to the door, sometimes there were broken/missing slats but other times they were intact. Most revealing was the absence of the lattice panel opposite the front door when Liz was standing near Thomas. (00:42:17 - 00:49:42)