If your narrative is correct, then the couple almost certainly would have been served better by documenting the violence and destruction themselves rather than coming off like armed idiots.
i'm not sure that a video camera offers the same line of defense as a firearm when you feel your life is in danger. after all, the incident was a straight up gun standoff with weapons on both sides.
The incident involved the armed woman walking towards the crowd while pointing her handgun at them. It's clearer in some recordings made from a different angle, e.g.:
So no, not a "standoff". Such behavior is certainly sufficient grounds to dismiss any claims of self-defense - lethal force is justified in self-defense when a reasonable person would perceive a threat of imminent death or significant bodily harm; but if you believe something to be a source of such a grave threat, why would you run at it?