Bad Coaching Styles

Hi, I am a mom of a 13 year boy who just had the worst emotional roller coaster HS baseball experience!! I am looking for help that deal with self esteem and self worth. I am a teacher of 25 years and have never come upon such an aggresive coach. We are going to the board about this and I need all the help I can get. All in all, he [the coach} wrote an email about my son and how he will never go on as a athlete...so on and so on....because they lost a tournament. My son read it! Obviously I am angry and disappointed and I don't believe this man should coach anymore. He has previously been kicked out of our league twice for cheating...Everyone is afraid to take him on. I would love to talk to someone on how to approach this meeting without sounding like the protective parent. He slandered my son and it is not acceptable. I deal everyday with the self esteem of children. It hi ts home when it is my son! Hopefully, you can help out.