Are we living in a "civilized" society or ...

Just yesterday(Thursday) morning, I was on my way to college around 7 something and got caught in the usual jam over at Old Klang Road. However, this was no ordinary day. While I was using that road, a taxi(Taxi 1) was right in front of me and we were moving very slowly until... *KRASH* he did not slow down and made a permanent mould of his vehicle's head on the taxi(Taxi 2) just right in front of him. Instead of going down and settle it mano-a-mano like the usual drama-filled "negotiations" by the side of the road, Taxi 2 just continued on without so much a wink. I presume that he must be renting that taxi and couldn't care less about it or maybe he's just shock resistant, I don't know.

Anywayz, Taxi 1's driver waved his hand out of the window, apologising profusely to Taxi 2 who was no more than a dot now. As I waited for his vehicle to start moving again, I was greeted by not the exhaust fumes coming out of his vehicle, but rather, a horrendous sight that I thought no longer existed in this civilized society. The man put on his hazard lights and just remained rooted on that spot and grabbed a handful of his(I assume to be) wife's hair (who was sitting next to him in the front passenger seat) and proceeded to BANG her head against the front passenger window a couple of times as I moved to the next lane. The taxi's sideview mirror said it all to me, I saw the lady's face remained emotionless, or as if this is just another of those days.

I'm pretty sure you would be asking by now, did I do anything to put a stop to it? I WISH I DID. You see, as I moved on to the next lane, that shocking sight did not register to me until a few seconds later as I was driving away from that scene. When I regained my composure, I thought of taking down the taxi's number plate by looking at the rear-view mirror, but alas, it was not to be, I was too far. That incident really shook me up and left me rather shocked for most of the journey. Now, I live with guilt because if I am given a second chance to relive that moment, I would have done something to stop it or at the very least tried to call the police or something. I feel for that woman. I really do. I just hope that someone else on that road saw that incident and put a stop to it and she would, I hope, be safe and away from that beast that should not be called a man.

What would you have done should you be in the same situation as me in the near future?