He left out the important word explained by the lawyer in the clip I posted above.
Lethal force is justified in defense of self when there is a “reasonable” fear of an imminent threat of death or great bodily harm. This forces the courts to view the situation through an officer’s (or citizen’s) perspective as the events were unfolding, not in an armchair quarterback freeze-frame analysis that assumes robotic, flawless reactions to violent chaos.
It isn’t a clear-cut case, but these sort of cases have been working their way through courts for a long time. Lethal force law is a comparatively mature body of law that has changed very little in generations. Even the controversial “Stand your ground” laws only removed what is called a “duty to retreat”, which was only required when it could be done in complete safety to yourself and those under the mantle of your protection.
For a very clear-cut case that @Brant_Drake just posted an update on, you can refer to the police shooting of Sonya Massey. The cop was just sentenced to 20 years, likely to serve 10.
Not to toot my own horn on such a grim subject, but I called that one correctly from the get-go. I’ve got a pretty good track record here on t-nation on the subject of lethal force.