I think that could still kill as well. Repeated shots break the ribs, and a subsequent shot pushes a broken piece of rib into the lung causing bleeding into the

I think that could still kill as well. Repeated shots break the ribs, and a subsequent shot pushes a broken piece of rib into the lung causing bleeding into the lung or maybe pneumothorax. Either that or the kevlar failing due to repeated shots. It's not meant to be shot in the same place more than once. Still more believable than Matrix style bullet dodging, though.