There may be a few exceptions but very few. Even if a horse is scared I would expected it to handle it without blowing up unless it's been gored then it gets a free pass. When a horse bucks it is not using its thought process it is reacting on instinct and that will get you in trouble every time.
There's nothing like the Rockies in the springtime... Nothing like the freedom in the air... And there ain't nothing better than draggin calves to the fire and there's nothing like the smell of burning hair. -Brenn Hill