Young, my only point was that blanket statements tend to ignore nuance.
I personally know a cop that used a head shot to stop a violent criminal. They guy had been shot two or three times with 180gr .40S&W Federal HST. One bullet had completely collapsed one lung. The criminal still managed to wrestle another cops gun away. So, cop #2 shot him in the head.
"It was less than fifteen feet and he now had a gun. I wasn't taking a chance that he would get the chance to fire. At that point it was obvious he was willing to do anything to stay out of jail."
The guy had a collapsed lung and severed brachial tube. Plus at least one bullet lodged in his intestines. He would have died eventually. Eventually was too long to wait. So, the necesary action was taken.
There are times when it can be articulated that a head shot was necessary to stop a threat. It isn't advised and it isn't something I would normally recomend. More often than not a good double tap between the nipples will end an atack. However, limiting yourself with never can get you killed.
I practice failure to stop drills. With my new 17 shot 9mm I don't anticipate much need. With my 5 shot .38spl I can see a real need even if it is only a two-on-one situation.
It is an extreme measure and you better be sure you can articulate a reason for taking such a measure. However, it isn't the instant conviction some on the internet believe.
Here's my credo: There are no good guns, There are no bad guns. A gun in the hands of a bad man is a bad thing. Any gun in the hands of a good man is no threat to anyone, except bad people.