I was watching this from the bigger picture, absorbing mostly that the contact with an unarmed attacker, grounding them, then pulling and firing on them during the struggle may work for military, but LEOs and civilians will have a really hard time justifying their action of cranking off a round in an unarmed attacker, especially if they are on top of them.
So...I like Hock's method, either holster the gun and beat on them, or beat them with the firearm. Firing only if there is no other option.
The other thing I noticed, was that that firing range tactic of pushing off then back peddling and firing may be lethal for both parties if the guy is armed. I LOVE Hock's First Blood exercise, running in and overwhelming a gunmen who is drawing on you, while you keep your firearm holstered. You really do live about 80% of the time, using airsoft to testify the results....
These guys should pay closer attention to the details and run the sims or airsoft with their training...and a forearm does shit, it takes a whole lot more if the guy is pissed, stronger, hopped up on drugs, or otherwise insane!