This is pretty much the worst nightmare of every parent with kids in public school, disabled or not, neurotypical or not.
http://shine.yahoo.com/parenting/stuart-chaifetz-secretly-tapes-autistic-son-school-discovers-220500111.html Long Story Short:
Single father Stuart Chaifetz begins receiving reports from the school district about his autistic son, Akian, attacking his aides and teachers. When a behavior therapist attempts a control test to provoke Akian to physically acting out, and fails to obtain that result, Dad wiretaps his son to find out just WTF is going on in his son's classroom. As it turns out, his son is being harassed, insulted, provoked, and generally bullied by his aides and teacher. When Dad brings this information to the attention of the school district, one of the aides is fired but one other and the teacher are retained and reassigned to another school.
At the risk of invoking "the Titanic was a big boat" style understatement, the recordings attached to this document are extremely upsetting at best and homicidal rage-inducing at worst. If you listen, do so with that in mind.
Your humble authoress of the opinion that reassigning a proven abusive teacher from one school to another is morally indistinguishable from the Catholic Church reassigning a known pedophile priest to a new parish -- there is no meaningful punishment for the abuser, and a new vulnerable population is put at risk. The remaining teacher and aide in this case need to be fired immediately, and if the teacher's union objects to this course of action, they need to seriously fucking reassess their priorities.