I agree that there was a good outcome. But I don't agree with some of that explanation for it. I think it's difficult for me to understand how being in charge of a one-ton weapon can of itself make someone less morally responsible for their actions because they might be subject to a phenomenon called road rage. I think being in charge of a car should make them subject to even more stringent moral duties than the norm. This second idea that drivers are especially weak, I think should be rejected. The criminal law surely properly allows a partial defence on moral grounds (or other partial moral exculpation, e.g. at the sentencing or charging phase) only for the most extreme cases i.e. insanity, automatism, loss of control from appalling physical abuse over a long period of time, but not for the everyday matter of driving a car around strangers.
I am not going to unpick this too carefully but I got the rough sense that maybe you felt that the purpose of sentencing and charging in this instance was to make reparation to each of the victims - so that having two victims (each being the victim of the other) meant that a lesser charge/sentence was required to do justice. I have to disagree. I'm in the camp that thinks the criminal law is properly concerned with wrongs or potential harms against society. It claims a monopoly on retaliation partly so people don't feel driven to that themselves, but that doesn't mean it's doing it for their benefit, but instead society's (imho). That said, by my own argument, you may have a point - if the means by which feuds start is a blow to someone's honour, then if each of the parties have hurt the other's honour, then maybe the criminal law has less danger of a feud to prevent. But there is still their harmful action to make an example of generally, as well as its intrinsic wrongful content to punish.
I think you're right there is something oddly fair about reducing charges for both participants in this particular instance - bu mainly because in this case it preserves their careers, not because they already made each other suffer a lot. But I reckon you're right that honour harmed equally, could be a reason why it would be permissible to press lesser charges (albeit ultimately for the career reason, it's not a good enough freestanding reason on its own imo).