At the first place I shouldn't mention his nationalities but I am pretty sure what nationalities he is... But that doesn't matter. FYI we were driving at the slow lane. We can accept if he only honking, flashing etc. What make us really upset why he suddenly dangerously breaking his car in front of us and he did so many times to provoke us?

My question are:

1) Do this "uncivilized person" have the authority to endanger another life even though we are driving at the fast lane?
2) If this thing is happening again in the future what is the best we can do? Just ignored the person who are enjoying to endanger another life?

Maybe if something very bad happen to him/his families on the road then he will realize the important of "appreciating other people life" OR maybe he doesn't care at all...