Further, I believe that a reasonable person would assume the worst intent. In the case of a home invasion, it is difficult for me to see a scenario where I would hold the homeowner responsible for killing the invader if I were a juror.Once the barrier of a home is broken all bets are off. You didn't decide to make your stuff worth more than a life. The person breaking in decided their life was worth less than your stuff. Besides, I don't know their intentions.
I understand the idea that a citizen can't unilaterally decide to be judge and juror. It's easy for a normal un-trained dude to misinterpret a situation. This is one reason that I would not shoot at someone stealing from me outside my home (lawn, shed etc.). I do understand the anger that it brings, having watched people steel my stuff before. I just personally have determined that I don't trust my senses enough to make that choice.
However, when they are in the structure that you sleep, I am in a situation so vulnerable that I have to believe my senses. The same barrier that they had to enter (walls, locked doors etc.) is now a barrier for my family to get out. The person in my house has already done something that is so violating and over the line of ethical behavior, I have to assume that here is no line that they will not cross. Once someone enters your home, you are forced to assume the worst intent. That is actually the most reasonable assumption in my opinion.
Having said all that, I have determined that at this point, a baseball bat is my go to weapon should I find someone has invaded my home for a number of reasons. I'm not 74 years old and that may change along the way. I am not going to judge someone like my one neighbor who has come out of his house to confront thieves with his weapon. I do hope given the proximity of my bedroom of his home that he does not shoot me or any other neighbor by mistake. At his age, the baseball bat is not the defense weapon of choice.