That one deer, the deceased one was quite a bit bigger in weight than the survivor/winner. Maybe it is not the size of the deer in the fight, but the size of the fight in the deer. It could be the larger deer was older and with the stress of the rut the larger deer was already weakened before the fight. The survivor seems as if he was still pretty tired out yet, didn't even leave quickly when humans were that close and he had the chance. Except for the chance happening of those guys that other deer's days may have been numbered also. That guy may see the survivor under his stand in the future.