I respectfully disagree with your statement about "...it comes down to personal risk acceptance" No matter how much the photographer is willing to be in the line of fire. And no matter how much the trainees are willing to "...send bullets whizzing past his head,...". There are supposed to be fully trained and non-compromising Range Safety Officers and the Head Range Officer which should never have let this occur. It goes completely to the integrity of the systems and the trained range personnel put in place at shooting ranges all over the U.S. If these trained RSO's are willing to compromise the integrity of their training and certification program, plus the operating rules set out then why do we even have these things in place to keep this from happening? If the RSO's are NRA trained and certified (Or another certification) they should lose their certifications. The insurance company the range is insured by should cancel their insurance.
I can't believe this was not only allowed to happen but that it was recorded and put up on YouTube.
What if (and I don't know if it was) this training occurred on private property, run exclusively by this Tactical Response guy? I 100% agree that 1) IF there were any certified RSOs there, their certifications should be revoked by the applicable agency; we don't know that there were, and 2) if I were a decision-maker at the insurance company that holds his policy, I'd either revoke it so fast it would make his tatical-operator-bearded head spin, or charge him a premium equal to the amount of the policy payout.
The key thing for me here is that as long as EVERYONE INVOLVED is aware of, and accepts, the risks involved, I've got no authority to tell them they can't. I can say that they SHOULDN'T, but not that they CAN'T. If this was happening at a range where the range operator was unaware of what was going on, that would be a foul. If I operated that range, they'd be ejected, never to return.
Like I said, I wouldn't participate in that activity, either as a photographer or as a shooter. BUT, if I were on my own land, with a group of people who all understood and accepted the risks involved, who should be able to tell me I can't?