Hugo was like that Bubba. He was still very much bright eyed, happy and still cheeky as always. Hence so hard to make that final call. But knowing that he would always be predisposed to injury and most likely would never be even paddock sound, it wouldn't have been fair to keep him going.
As for seeing them still run around with the herd, most will. My mare tried to take off on a front leg so badly broken that it was literally swinging in the breeze.