When Joel and Ellie are surrounded by horses, the lead man's mask covers his face, then is below his nose in one shot then is covering it again the next.
When Joel is taping his boot, he is wrapping the tape from one direction but when the angle changes to a close up, he is wrapping the tape from the other direction. The scene then switches back to the original shot to show Joel ripping the tape and it switched directions again.
At the end, while Ellie tearfully pleads with an unconscious and wounded Joel to wake up, the horse in the background of the shot clearly doesn't move or put its' hind leg down.
Everything in Jackson looks clean and brand new. But with the community being self isolating from the outside, all consumer products would be at least 20 years old, worn, and patched with ad-hoc repairs.
Marlon claims to have lived in the cabin for more than 50 years (before Joel was born), and yet it's clearly not winterized, with visible gaps between the door and the frame.
Joel would have been suffering from hypothermia after sleeping outside without any protection in the Wyoming winter.
The film crew is visible in a wide-angle shot of Joel and Ellie crossing a snowy bridge.
In the establishing shot of "the river of death", several crew members are visible in the bottom left hand corner.
When Ellie goes to greet a foal in Jackson in the stable, the hand of a crew member is seen making sure the foal's head is in place.
It makes no sense that a survivor like Joel would pull the blade out right after being stabbed, knowing how much this would worsen the wound. This was entirely out-of-character for him.