Frustrated and disappointed.

I apologise in advance for my long rant! After years and years of my son being failed and let down by our educational settings I am so incredibly angry. It took years and years for him to get his diagnosis and 3 assessments from CAMHS to finally be told yes he is ASC. He has been kicked out from varies schools because he has meltdowns, he has tried to strangle himself, he is violent at home, we have had police involvement to the point they took him to hospital under the mental health act for his own safety. Anyway this is just a catalogue and brief outline of my frustration. Several weeks ago he had a meltdown at school, he is 15 and in year 10 and been at the school for over 4 years. The meltdown resulted in a permanent exclusion which I knew was down to poor decision making by school. I have fought and fought for my son and since the exclusion more and more details of the incident and how school failed him that day have been brought to my knowledge. I attended another school meeting last week and they have over ruled the exclusion and he will eventually be allowed back!!! I truly believe this exclusion happened because of their failings and understanding of autism. I wonder does anyone know where I stand legally if I wanted to persue a disability discrimination case even though school are dropping the exclusion?? I have no legal knowledge so any advice would be great. Thanks

Nic