You may not know where he is coming from, what is motivating his behavior. You may never find this out. You do not need to know why. So I would take his behavior too seriously. For all you know, his weenie maybe on the line with his father. I am sure you are not the only person he has yelled at. Just do you job to the best of your abilities. I am sure this is what you already have been doing. This is all he can expect from you.