I don't have advice to offer but I had to reply to your post because I am in an extremely similar situation and can relate to your disappointment with the school and concerns for your child. My son was identified at the end of 8th grade and is in 9th grade now. He is so far behind on some essential skills that I fear he may never catch up. I've spent thousands on tutoring (which I don't have, I took out a home equity loan).
I am very glad you have a lawyer but am so sorry you need one.