There is 2 lessons here. Don't ever react to petty road incidents in foreign countries. Or even at home. Just eat it. It is not worth it.
And also. It is easy to sit here and dunk on this guy. But imagine you just had your worst day ever at work, and you are driving home. Some foreigner cuts you off, fingers you, blasts you with his horn and hammers your front fender as he drives by. You might be the one with that gun in your hand, if you are the type that owns guns. Leave your guns locked away at home.