A horse would rarely try to get revenge on a rider or any other person for that matter. Except when the human is acting in a cruel and barbaric way, like the man in this video. We can fully say that the horse definitely had it in for the rider as he seemed to be enjoying pulling the reins too hard and hurting the poor horse.
As they were in the middle of a feast and a parade the horse did not want to put up with the rider and noise around anymore and just reared and the rider dropped deadly scared on the ground. It looked like the horse got its sweet revenge and as a matter of fact, I would have done the same if I had someone on my back constantly yanking on my mouth.
This horse in this clip held a grudge until the perfect moment came and did that especially in front of all those people. Sometimes abusers deserve to be taught a lesson.