Gun writer & sworn LE officer Massad Ayoob has put out a # of gun press items over the years(1980s/1990s/2000s/etc) about how cops & armed citizens were seriously wounded or killed by subjects they thought were "down" or no longer a threat.
I recall a recent Ayoob item where a police officer shot a subject in the chest, he lunged at her, killing her, then he fell over dead.
As the GZ defense team's own medical expert(a veteran forensics doctor & former US Army officer who ran a wound ballistics lab) testified, human beings can keep fighting or be ambulatory even when seriously wounded.
Clyde F