I suspect (but have no proof) that someone that big is likely on recreational pharmaceuticals and will probably not go down immediately. Also, a mag dump is to some in the legal profession a clear sign that you feared for your life, etc. For me to be in the same relative position as the landowner here, the other guy would have to be about 6’8” and half-Samoan NFL defensive linebacker size and strength. You bet your arse I’m going to be firing fast and furious until he stops in such a case, and someone that size is going to take a *lot* of stopping.
Certainly not questioning the tactics.
I agree that the point of us I g jufitied lethal for us to stop a threat, one shot or 30.
The only concern following such use of force or pre-stating the mag dump as you describe may not be reasonable in any given situation and such statements have used by prosecutors in cases of lethal force and leads towards predetermined intent not a case by case response.