knockout = death in the game already.
This of it this way: When you die in this game, it means you have 0 hp. Maybe your character is knocked out, maybe you had a limb cut off and can no longer fight and bleed out on the ground over the next hour and a half. Maybe you die instantly.
0 hp (death) signifies your player character has been rendered unable to continue fighting. That's why you can die by getting stabbed in the foot 6 times, or whatever.