Assault on Visitors

The following from TOB posted earlier today.  Scary stuff.  

Yesterday, some NOB friends visiting our area were in their US-plated vehicle in Ajijic when a Mexican male seemed to deliberately hit my friends' car from behind.(The man was stopped a couple of feet away then suddently lurched forward clipping the bumpers.) Without even looking to see if any damage had been done (it hadn't) the man jumped out of his car and ran to my friend's driver's side window and started yelling, cursing and demanding money (in English). Obviously just another shakedown attempt.

BUT then the Mexican slugged my friend in the face (through the window) as hard as he could. Although my friend was bleeding, he had his wife with him, held his temper and drove on. They didn't have cell phones operable in Mexico or they would have called the police.

They took down the Mexican's license number, intending to report the incident. But four long-time residents told then they would be wasting their time and that if my friend had hit struck back at the Mexican in self defense, he as a foreigner would have been arrested.

Is this true?

Regardless, I was so saddened to hear my friend say the attack, "Sure took the shine off Mexico!"  What should they have done, if anything?

Thanks for the heads up.  That used to be a typical ploy and happened to me when I was living in Guadalajara - he demanded money from me because he said I stopped suddenly and he had tapped me in the rear end - was driving a junker.  Fortunately the light turned green and I took off - he followed but I too some quick side streets and avoided him.  Scam probably in fresh from Guadalajara.