BBM. I don't think we can draw that conclusion, at least not yet.
If EN's claim is true that he saw someone in the green car waving a gun or holding a gun out the window or pointing a gun at EN, and if the person doing that was Brandon, then Brandon is probably guilty of brandishing. (I'm assuming that Nevada and/or LV has laws against that.) Pointing a gun at is generally a threat and can generally be considered some type of assault. So Brandon may well have broken one or more laws at that point -- and that was, AFAIK, before EN fired any shots, which just makes it worse for Brandon (IMO).
Also, I think the details of exactly what happened are still very much up in the air regarding who followed who, who did what, who was driving, who shot first, etc. As far as I can tell, we don't have enough verified, confirmed details about how this whole incident unfolded to draw any conclusions about who might have broken which laws.
I'm not asserting that Brandon is guilty of anything. Brandon may not have broken any laws. Or he may have. I'm only asserting that we can't know for sure at this point.