I would think the husband drawing his firearm is more justified than the wife... he cannot see all the interactions on the other side of the vehicle. His wife has seen something and drawn her firearm; the husband has to rely on his wife's observations, and draw his firearm to support her.
That is no different to Police. One officer see's something, draws their firearm, the other officer, who may not be precisely aware what caused the first to draw, also draws their firearm to support/protect the first officer. The decision to shoot is made by the gun carrier alone, based on what is presented to them.
The provocation is from the coloured lady, and her two offspring, who follow and continue to berate the couple (targeting the pregnant woman), and the mother of the girls who appears to hit the car, and then cry out that they drove into her. I wonder why there is no outcry about the
mother's racist attitude?
The extremely pregnant wife may lack the physical capacity to fight, allowing her to move to a firearm earlier. It also appears she is backing up, and the 'mother' is going forward, the aggressor still, by the cries of the daughter.
None of this, to my way of thinking, actually justifies the transition to a firearm, rather than departing the scene and calling Police. The wife actually asks the husband to call the Police; the aggressive mother says something about calling her husband.
I also have serious doubts about the assault by Police, in America, drawing a firearm and pointing it as someone without justification; I live in Australia, I worked as a Police Officer, including high crimes areas, and rural single officer patrols. In 16 years I could count the number of times I drew a firearm, on two hands. I could count the number of times I drew a firearm and pointed it at someone with a high probability of shooting them if they didn't comply, on one hand (a few fingers - I had to change this, because I don't like to dwell on things, but the number was actually bit higher than a few fingers, when I went back and added up - only a couple were two way shooting range type things).
The sight of a drawn firearm is a use of force, under some circumstances turning the firearm side on, so the person can clearly see what is in your hand, may be sufficient (person with a knife, some distance from you). The transition to pointing to someone is a further heightening of the use of force, and in most jurisdictions an assault.
It was preferable to have two hands available to deal with someone; I found the long baton an effective 'tool' for force multiplication (if required)... I'm not as much of a fan of the ASP baton, although its capacity to be carried and have available, is a benefit.
This matter will be settled in a court, for the people originally verbally attacked, and pursued, by the mother and her daughters... so the original aggressor may feel 'justified' that her poor behaviour, her racist behaviour, her aggressive behaviour, which she is teaching her daughters, is also OK. That could be one of the sad outcomes of this, either way.