I might have done the same. Perhaps cause I am in the same age group. If I was holding a sword, and the guy knew he would die... and he still lunged... well, he is stupid. He should have expected the worst being a criminal. If I can defend myself, my property, and my hard earned possessions against someone who is a criminal, why shouldn't I? Just because some would consider it brutal does not take away from the statement's validity... cancer, drunk driver, cops, and thugs never cared for my friends' lives - why should I care about a burglar's?
If you had a weapon to defend yourself with, and the burglar lunged at you, would you drop it, and say, I don't wanna kill you, just take whatever? Crazy.
I understand though, why you guys would like discussion on this topic to end, and if the prevailing opinion is that it should be closed, so be it. I just feel that there is a lot of opinion against the sword-wielder - I can understand where he is coming from.
Anyone who's ever been in a similar situation especially at that age, would not want to back down and "bend over" so to speak.