Continuity mistake: When Dale falls through the roof to his death, he lands with his head facing towards the right, but when they zoom in on his body, he is facing straight up.
Continuity mistake: When Cooper and Leah Tilson first find Devil's Throat, the time of day changes between shots. When they leave their car, it is already getting dark. In the next shot, while uncovering the hole, the sun is shining. It is dark again in the next shot.
Continuity mistake: Dale puts his cigarette out twice in the dinner scene at the house.