What you are going to watch is some falls and fails, some horse accidents happening and not because of the horse’s fault but because of something else. It might be the rider’s fault or something that has scared the horse. Also, this is not ‘sick’, people fall off horses all the time. Someone falls off without fails every weekend and this is normal because it is part of learning how to ride.
Maybe the rider kicks and pulls at the same time, giving the horse two different instructions making the horse rear or buck. And this causes injuries. Sometimes riders and horses can get in dangerous situations and both the rider and the horse can get injured. Anyway, horse riding is not all about danger and death, it is about learning and becoming patient and understanding with the animal. What is important is that when things go wrong you need to laugh it off and get back on. It is not easy to stand on a horse, if you are not focused and concentrated when your horse makes a tiny movement you are off. We all love horses, we all ride differently, some do it better and still horses are our passion!