That argument that one can't just BELIEVE his life is in danger - but one must assume what a NORMAL/AVERAGE person would believe - is BS.
There's a very obvious flaw in that logic.
Some men are not average in either skills or experiences. There are men who served the US in the military in war - and they were conditioned to eliminate their enemies - to protect not only themselves - but their brothers in arms.
Once combat is initiated - and the shooting starts - an experienced combat soldier will kill everything in sight as this is required - and is NORMAL.
Unlike a guy who works in a dry cleaners and was faced with the same threat - mistakenly THINKING he would only shoot them in the leg to end the attack, as most candya**es might think.
That case says he put five through the windshield, and the remaining rounds through the driver's side window.
That's called, a "flanking" movement and the ideal application of a crossfire shifting to defilade fire. This flanking movement is one of the oldest, most effective tactics ever used since who-flung-the-chunk thousands of years ago.
NORMAL to everyone - in combat.
Then, there's the combat mindset developed over time - in combat - especially when attacked. You must remain calm and work the problem - until the threat no longer exists.
Flanking is often just instinctive - as you avoid their frontal threat, and hit them from the side - where they're more vulnerable to your attack - than you are to their attack.
So I'd suggest the standard of what's "reasonable," or "rational" to be measured by what is "normal," is a very vague non-definite standard.
What's normal for me - won't be normal for a candya** who's never taken scalps. But I won't be following up on the street with a follow on head shot in each one as I'd normally do after a firefight.
The so-called "law" is FOS in matters of defense, justification, and reality.