The validity of the "One shot stop" has been thrown around since the study was done. You can't really argue the results. The results are what they are, but it is to be taken as is, not a definetive study saying if you use brand 'A' it WILL stop an attacker 91.2% of the time. There are many, many stories about good guys, bad guys, soldiers & civilians taking massive damage to the torso & surving to fight on, sometimes even to live through it.
Probably better than shooting jello blocks or using some formula to give a shooter an idea of what works better, and some rounds/bullets do work better than others. The studies are real world shootings, take the results for what they are worth. Bottom line is no handgun round can be determined to stop an attacker reliably w/ one shot, so as said before, shoot until your target is down.