Also, the mere act of picking up a weapon and taking it along to a planned confrontation implies premeditation, particularly in the case of an illegal weapon.
I’m not defending the dead guy, just pointing out that the gentleman who was just sentenced was not himself innocent under the law. AFAIK, this would be true in most US states, too.
With probable exception of Texas. :)
Taking a weapon means self defense and is what you would have done