I keep thinking that if your husband is not working against you on getting your son's educational needs met, then does it really matter if he 'gets' your son the way you do?
The great part of two parent families is having two different approaches and connections to the kids. He may be able to meet your childs needs in ways you don't 'get'. You may meet your childs needs in ways he doesn't 'get'. As long as you aren't having to fight your husband as well as the schools, let him understand your son his own way.