I can explain it to you, but I can’t comprehend it for you...
The 21 foot rule is about avoiding getting stabbed. That is its purpose.
If someone is “inches to a foot” (various news reports) from you, with a metal object in their hand, then it looks like they’re going to be able to stab you.
I shouldn’t have to point out the obvious truism; That “inches to a foot” is well INSIDE of 21 feet!
Officer Marin saw his partner in that situation and reacted accordingly.
It DOESN’T MATTER if the partner wound up in that situation through their own incompetence, or whether or not they might have been able to overpower Mr Stabby. The reality still is that they, according to Marin, appeared to be in immediate danger. Now maybe that’s true and maybe it isn’t, but I’m going to give him the benefit of the doubt until I have reason to believe otherwise.
If I was a cop I wouldn’t want to be stabbed. Having said that, this cop wasn’t being attacked with a cutless or samuri sword. He likely had a baton, or mag light that he has been trained to use as a weapon to disarm perps. Combine said training with the perps physical condition, makes this shoot patently absurd.
A cop that is within arm's reach of a one-armed man in a wheelchair should be able to see what is in his only hand.
The reality still is that they, according to Marin, appeared to be in immediate danger. Now maybe that’s true and maybe it isn’t, but I’m going to give him the benefit of the doubt until I have reason to believe otherwise.
You have been given more than half a dozen good reasons to believe otherwise but you have chosen to stick to an entirely irrational position.
I am absolutely amazed that I have to point out (again) that the '21 ft. rule' is utterly irrelevant if you have already stipulated that the person is only "inches to a foot" away.
Logic is definitely not your forte.