That was his or her one and only chance. If they blow that, the end result is upon them.
Now bear in mind, while I have no desire to shoot or kill anyone, the possibility is always there and I have accepted that fact. I cannot, and will not, be responsible for someone's failure in the victim selection process.
While I have no desire to shoot or kill someone, I also cannot afford, for my safety and the safety of those within my abode, to be concerned about the one that put me in the situation in which I have to discharge my weapon. They, at that point, cease to be a human being for that fraction in time, and are A THREAT to my life and the life of those I care about. They will be dealt with accordingly.
I have pre-drawn lines in the sand. Once those lines are crossed the only response from me is lethal force. I suggest that those that are dithering about sit down and rethink their commitment to taking a human life. If questioning the commitment, go hunting and kill an animal. While not a human, it does involve death and the taking of a life. Some people will learn that they cannot kill.