This is when a race horse kicks so hard it flips over onto its back and would have hurt the jockey if it landed on him. It is a really dangerous situation and it is pure luck that the jockey did not end up injured.
We might say the same for the horse as well. He could have broken his neck if he had thrown his head back too far. This horse nearly killed himself and the jockey as well. Although it was a fine mount by the jockey the horse seemed to be agitated and did not want to be ridden and the reasons may be various. He might have had the bit too tight or the saddle not put appropriately and this resulted in the accident. Anyway, we should always be careful with horses as we do not always know how they react but one thing is sure that we should always treat them well, show them love and respect.