Corrected entry: In the movie, it seems like king Edward dies at the same time as Wallace. In reality, Edward I died in 1307, two years after Wallace.
Corrected entry: When throwing rocks at the bones as a boy, William Wallace uses his left hand. At the wedding, when he throws a rock at Hamish, he uses his right hand.
Correction: It was common practice in those days to encourage children to use their right hand - he might have been naturally ambidextrous but was forced to use his right hand, hence his skill developed with that one.
Corrected entry: In the very first fight, Gibson had a flail and antlers. After he hits the 1st guy, he falls from his horse with flail in hand. When attacked by the 2nd guy, a sword is now in his hand and he blocks an attack with it.
Correction: Wallace drops the flail after he falls off the horse and picks up the sword of the first guard he killed.
Correction: Exactly - the movie only shows Edward I gravely ill. There's nothing in the film to suggest the king is dying as Wallace is being executed; rather he is suffering due to his illness.