I agree, that some of the things shown in the Gunsite video are something I would not agree with. On that square range, her scanning technique is safe, for that environment, and, I understand that showing that technique is meant to teach a valid point, but, true, when in a 360-degree real world, well, not so good.
Of course, my personally-preferred 360-degree real-world scan would get me thrown off a square range. (Averted muzzle*, and footwork that moves me in an arc, away from where I was standing. The more available space, the larger that arc. Learned in the real world of street policing.) At a formal range, one has to stay within their rules.
I disagree with the scan being done with a cocked hammer, as shown in the video. Personally, I see the cocking of the hammer as being analogous to the long DA part of a DA revolver’s trigger stroke. I will not cock the SA’s hammer unless I perceive a target/threat. Cock the hammer as the muzzle moves into alignment with the target/threat. The “dead” trigger, that exists when the SA’s hammer is down, is a most compelling safety feature.
I realize that I may be marching to my own, different drummer, here.
*My averted muzzle means that I can be surrounded by family, friends, colleagues, and other no-shoots, while I scan. Think SUL, or what I learned as an “Averted #2,” from SouthNarc. (SUL really hurts my aging wrist, so is used only for very brief moments.)