In the case of which corner fell, I think they changed it on purpose, since they wanted to take the story into the courtyard. The captives who had their hands and feet chopped off weren't captured as they lay injured in the courtyard, historically. Instead, they were folks who were sent out of the castle by the rebels, to reduce the need for food. And then some had hands and feet cut off by King John (boy, he was a right bastard, wasn't he?).