It turns out that a lot of the historical travesties in Braveheart aren't actually Hollywood inventions. Wallace's romance with babesome English royalty? Straight out of Blind Harry's 15th c. poem. Mass hanging of Scottish nobles in a barn based on misunderstanding of earlier account? Blind Harry. Nonexistent assault on York? Blind Harry. Undocumented encounter between the Bruce and Wallace at Falkirk? Blind Harry.
However, Gibson's team still get the blame for the anachronistic blue face paint that makes the Scots look like homicidal smurfs. And filming the battle of Stirling Bridge without the bridge because it got in the way. Which is a lot like filming storming Omaha Beach in Omaha because it's more convenient.