Law's intended to encourage that
if you pull, you're
damn sure your life is in danger and that pulling a weapon is the only choice you have available to you. From what I remember of the courses and instruction I've had, you only pull a gun if you're absolutely sure your life is in danger, and once you've pulled, you give one warning that, if ignored, is followed by a shot to center of mass. Deadly weapon is to be used if and only if deadly force is required. If you've pulled a gun it is because you're in a situation where killing them is the only option available. You don't wave the gun around, you don't fire warning shots, etc., so forth, so on. You don't pull unless you're intending to kill, period. You can give warning that you're armed and whatnot beforehand, but the gun does not come out until it's going to be used. S'how it was explained to me, anyway, insofar as I can recall (it's been a few years, honestly.).
As always, there's vagrancies based on area and situation, but... yeah. That sort of law isn't intended (isn't to say it
doesn't, but still) to encourage you to kill instead of scare off, it's to encourage not pulling unless you
need to kill. And, to re-emphasize, the specifics of when you can and cannot legally pull a gun varies by state, sometimes wildly. Shit gets confusing, s'pretty patchwork regarding a lot of things, from what I understand. And yeah, sometimes things are terribly wrong
Re: The latter bit, though, presumably that was covered in the case.
If escape wasn't possible, then it may have qualified (presumably, gods know I'm not a lawyer and the legal specifications are what they are). Apparently judge and jury decided otherwise... s'
entirely possible they decided wrongly, but barring more information (which the article, at least, didn't provide) I wouldn't say more with any certainty. It does kinda' seem like getting the gun and then going back into the house (as opposed to staying in the garage and waiting for the threat to come to her) would disqualify the SYG stipulation, though.