Plenty of great advice/comments already but in my opinion, it is just another opportunity for parents to prepare their child for life. I think we all sometimes make the mistake of looking at high school athletics and all that goes along with it, including the recruiting process, thru a microscope. I work in education as well as coach and we talk all the time about not judging a student without fully understanding family dynamics, etc. Helps me look at everyone I interact with in a different light.
If it were my son, I would talk about the many reasons why the RC could have been an ass, none of which have anything to do with my son personally. Maybe your son's call was not the first that the RC had received that day. Maybe his job is on the line this upcoming season and he has a family to support. Maybe the guy is just a bad apple. Again, none of those reasons have anything to do with your son.