I generally try to avoid guilt by association or ad hominem judgments but in my experience, the statements out of any organization with "Justice Project" in its name will be so much leftist garbage with only a passing relationship to facts or evidence. They were not the DA or the judge or the jury, simply activists trying to get the press to repeat their propaganda.
I'm not surprised at pressure on the DA to drop the remaining charge if the DA overcharged in the first place -- leaving race out of it, person A pissed off persons B and C by tailgating them. Person B then cuts off person A and doubles down when traffic comes to a stop by getting out of the vehicle and proceeding to pummel person B through the open window. Big surprise in a state that sort of observes the Second Amendment that person A then defends himself the only way he can, being seated.
Why would a DA charge person A with murder over this except to push "guns are evil" and "you don't get to defend yourself, the police will defend you"? (Even though the latter statement has been shown false repeatedly.)