As you so rightly say it is ok to be emotional but not create the mess of it. Good that you were able to take up for your friend and give it back to that jerky guy. Yes our environment, diet everything impacts our behavior. In a way it is sorry for him to be that way, but at the same time we getting carried away while dealing with such people will not help.
Thank you for sharing your wisdom :-)
And it is ok to be on FB or any other SM ;-)