Revealing mistake: The room Jim and Neville are in is equipped with a double interior wrought iron security gate that appears to be automated, but it does not actually function like a motion-sensored one typically would. The double doors are open before Neville's bookkeeper exits, and where Neville is standing might explain why both sides of the gate are open and stay open until the bookkeeper re-enters. However, they close behind the bookkeeper (and at different rates), even though Neville has not moved. (00:09:26)
Revealing mistake: Jim parts his hair on the left side. The stacks of his books on display in the hallway include a photo of him with his hair parted on the right side, but otherwise looking the same. Hair that is persistently parted on one side will not easily part on the other side and lay across the head in the same way. (The image was reversed). (00:25:20)
Revealing mistake: When Amy was walking past the bicycle rack along the road, the background changed a few times (indicative of using a green screen) and she walked past the same bicycle rack at least two times. Sometimes, there was no bicycle rack visible, although Amy had not walked very far. (00:51:00)
Revealing mistake: The (CGI) wind turbines were awkwardly spaced and incomplete in spots. Ten or more sets of blades (center left of screen) had no towers attached to them - just blades "in the air." The blade lengths varied from tower to tower instead of being uniform and appeared to be disproportionately small relative to the tower heights. Nocelles were absent (or not visible like they should be), so there were no anemometers attached. Most towers did not appear to have a transformer at/near their base. (00:59:07)
Revealing mistake: Neville pushed Jim's back against a metal garage door/gate in the alley. Front views of Jim show him with his back (and head) against the door, but rear views show him out in the open (away from the door/walls/buildings). (01:01:42)