The law states that self-defense is the last option. You do have the moral and legal responsibility of using deadly force as a last option, and yes retreat comes first.
It is not in his post but I am wondering what law that is. Even in Texas, before the Castle Doctrine was passed, deadly force can be used on an intruder without fear of criminal reprisal. The current Castle Doctrine that goes into effect September 1st removes the possibility of civil reprisal as well. (It was all too common for the families of slain burglars to sue those who killed the burglar.)
If faced with a dangerous sociopath, people have a moral responsibility to incapacitate him. That includes killing him. Whether or not anything else could have been done to stop him is academic.
I say "supposed reader" not because I think that Kim would contrive such a missive himself, but because his regular readers would not send a message like that - except for maybe someone wanting to play devil's advocate - and that he and others like him receive plenty of mail like that as a matter of course.
Getting back to my point of this though...
The last part about "retreat comes first" is something that bothers me. There are many states with laws like this.
I have not been in the situation of facing a burglar in my house. Nor do I hope to ever be. </standard disclaimer> I cannot know for certain what course of action I would take but my attitude is thus: If I "get the bead" on someone who has broken into my house or car, he has the time it takes for me to pull the trigger* to convince me that he surrenders his life and neither he nor any of his cohorts are a threat. I will not yield the element of surprize to say, "Hands up!" The only warning he might get is the chambering of a round. I will not risk losing anything to take the time to ascertain his situation.
It is his duty to not to be there. Failing that, it is for him to surrender, not retreat. If he tries to run I will kill him. If I think he may be with others I will kill him. If he is armed or if I think he has harmed anyone in my family I will kill him. If I think he has taken any of my possessions - you guessed it - I will kill him.
Some may argue that material possessions are not worth human life. I disagree. However, if that is the case, it is best that it not be risked by stealing.
The time that it takes to defend my house, my family, and my sacred honor may be precious little. I will not waste it.
* He had better hope that I have a gun on me. Any other item such as a golf club, kitchen knife, or my hands and I will not even take the chance of allowing him to surrender. My having a firearm affords him that little bit of latitude.