I would agree that a good cav should never die like this. One who maneuvers properly, angling to ensure his lance is on the correct side, while at the same time flaring away slightly at time of impact so that the 1h with short weapon cannot reach the horse. there are A LOT of bad or lazy cav out there tho, who dont bother to maneuver properly cuz they are just so used to backstabbing people offering no resistance that they are surprised when an alert and clever infantryman actually fights back.