Continuity mistake: At the end when Jack (Ethan Hawke) is nailing the roof of his cabin he stops and looks around with the nails in his mouth. His head turns and the camera goes back and forth and suddenly the nails are in his hand. He then runs down the latter with no sign of the nails anywhere.
Continuity mistake: After being attacked by the bear and scratched on the arm/hand, Jack has no bandages or scrapes on his arm.