That looked painful as hell. Though bad in physics because horses are smart and they don't have strong legs for no reason. The horse should of jumped. If someone was to disapprove my theory, I would have to say this. Even though the mans weight plus the armor and the other stuff. The horses jump height would decrease but it wouldn't decrease that much.
The horse could either stop and the knight would just go flying off to the edge of the hill and the part of the hill would of broke and he would obviously die.
Any who, the animation was nice.