Continuity mistake: Burt is lying at the bank with broken leg flesh dangling. Next shot different angle, not dangling, then dangling again.
Continuity mistake: In the scene where Lewis and Ed are in the canoe after setting up camp and Lewis is bowfishing while Ed is drinking beer, Lewis shoots a trout. You can clearly see the arrow hit the fish just behind its head in a close-up shot. When Lewis pulls the fish in, the arrow is through the middle of the fish's body.
Continuity mistake: When Burt's canoe comes up between two rocks, as the wooden canoe breaks in two, he had just passed through the same two rocks seconds earlier. (01:02:05)
Continuity mistake: When Ed loses control of the canoe and is trapped between two rocks, the other canoe strikes his and breaks it in half sending him and all of the contents of the boat, including his hunting bow, over the falls. Ed tumbles down the falls with nothing in his hands. In fact at one point he tries to scramble out of the water using both hands in the attempt. Yet two shots later he suddenly has his hunting bow in his hands. (01:02:05 - 01:02:50)