A group of people breaks into someone's house at midnight with weapons and it's not a story that someone defended themselves, at all. Bringing it up is a distraction - and this entire HN thread is a perfect example of that.
If the guy hadn't shot, or had shot second, or if Taylor hadn't been killed at all, it wouldn't make what they did justifiable. The fact that their absolute negligence led to a situation where a woman died is just what makes this that much more important to focus on.
It is not moved to another section "for a snappier piece" as you put it in another comment. It is simply not important information, it is not relevant, it does not change the judgment, it does not change that the police are responsible for her death.