Continuity mistake: When Wallace tries to escape from the English with his wife, not knowing that she has been captured and executed, he is seen running through the woods screaming her name... As he's running he has a sword in his right hand. During the course of three or four camera shots, the sword he is holding magically disappears and reappears as different cameras shoot him. Then it reappears and he digs it into the ground as he takes off the English soldier's uniform that he stole.
Continuity mistake: Just before Wallace picks up the archer to throw him over the ledge, you can the archer has a tin looking hat around his head with part of his suit covering his head below the hat. In the shot from in front of the ledge when Wallace is throwing him off the cap has now disappeared before he has been thrown. The following shot as he is falling its a bit hard to see his cap but you see it come off.