Thanks for the responses. All of the above did not change the outcome of the game. My son, and hopefully the HC, will handle this a little better in the future. Lessons learned.
I feel, but I do not know, that the player, as leadoff, was getting on top of the plate as much as possible to shrink the SZ and was perfectly willing to get a HBP. In my experience of HS baseball, the batter usually gets the base on a HBP and the opposing HC THEN decides to confront the umpire that the kid has been crowding the plate all along and made no attempt to get out of the way (which is always too little, too late). This is just my experience.