An altercation like this does not happen out of the blue.
Belgian Man: Would you be so kind to move your car
Indiens: Take out sticks and rocks and start fighting
You exactly know that there's always a buildup, posturing, verbal escalation, pre-thread cues and such. And there came the sense of superiority in play, wanting to impress his GF, maybe Alcohol (an assumption of mine) and testosteron. I am talking about the pre-fight not the fight itself. Excuse me if that was not clearly written. Of course in a fight, MMA training gives you an advantage as every other martial art training does, there i agree with you.
So, how this would have been solved in self-protection (not self-defense there's a big difference - self defense is implying that you are in a self defense situation already) when you are trained in self-protection, simply you wouldn't be there, the fight wouldn't have happened because you have the situational awareness and walk away from such situations, they are simply not worth it. I am also not implying non-violence per se don't get me wrong - if you are in a code red situation you have to neutralize the threat without hesitating but the key is always awareness. It can safe your life and kids still have a father and not a dead one who was a hero in a dispute over a parking lot.