It is rubbish. Texas law treats all shootings the same. A firearm is deadly force, by legal definition, so the portion of the anatomy targeted is not part of the legal issue.
As the former director of the TABC academy, we did not rank the shooters for the simple reason that it was easier on the paperwork. TCOLE (or TCLEOSE as it was then) requires proof that the officers qualified by their standards, so that is what is kept in the records. When I went through the SAPD academy (back in what seems like the dark ages now), we not only scored the target, but gave an award to the best shooter in the class. We also wore NRA qualification badges and tracked them for the Distinguished Expert badge there. I am not aware of any case where the prosecutor, or even a plaintiff's attorney, basing any argument on the ability of the shooter.
I am also aware of the one case where a sniper actually shot the pistol out of the suicidal man's hand. One of the problems discussed was how far off target he was (he was aiming for the body not the hand) and how it would affect people's opinions of other police shootings by making them think this could be done at will.
He is a youtube clip of the shooting (but please ignore the obviously idiotic British narrator who is not familiar with our police wearing camo):
https://www.youtube.com/watch?v=BVnwkDbeARw