Other mistake: When Robert the Bruce returns to the battlefield at Falkirk, there are 2 children supposedly crying over a loved one. If you look at the blonde girl she is actually laughing. (02:12:00)
Other mistake: In one of the very last scenes of the movie, when William's friend Hamish takes out William's sword to throw it as a sign of honor for William, when Hamish extends his arm back to throw the sword he only takes a step or 2, but he does not hit any of the men standing in formation directly behind him with this 5 foot long sword.
Suggested correction: The blade on a claymore is 43 in which is 3.5ft. The men behind him were more than 3.5ft away. Plus, when he swings the sword, his arm isn't parallel to the ground, the sword is pointing towards the ground at first.
Other mistake: At the end of the movie when Wallace is being executed and the crowd starts chanting "Mercy," one girl towards the front left looks directly at the camera with her eyes twice in two different shots.
Suggested correction: Yes, it was done on purpose. It is the same child he locked eyes with prior to being hanged and while he is being disembowelled.
Other mistake: After the fight at Falkirk where Robert The Bruce is walking through the field, there is a woman walking checking the bodies. All these people clearly are supposed to be dead. The woman lifts the head of a man and then puts it down. After she lets go of the head, the boy picks up his head and looks to his side.
Other mistake: Near the end of the battle of Sterling after Wallace nearly hits one of his allies on the horse, look on the right side of the shot. An English man wearing metal armor is fighting some Scots. He doesn't make much effort, barely swinging his sword. The Scots fighting him also don't put up much of a challenge either.
Suggested correction: Because they're exhausted.