That depends-- on a huge number of things.
Honestly-- and I don't mean this to sound offensive, but it probably will--
did this teacher maim or permanently injure your child?  Place his life in danger?  Or just temporarily leave you both reeling? 
The reason that I ask is that there 
is (in my mind, at least) a lot of grey area in between clearly black/white discriminatory behavior.
I still think, based on what you've stated, that it comes down to a teacher who is ignorant.  I don't believe in 
punishing ignorance-- but in educating it, where possible.  
I say that as someone whose child was openly mocked in an e-mail passed around with a national club athletics organization-- by 
attorneys and coaches.   A disability that really can kill her.
Mentioning that only to note that I get what you're feeling-- maybe even and then some, truthfully.
But I think that you're probably operating in "I'll get even with YOU..." or perhaps "How dare you treat us this way!!"
Neither of those things has a reasonable resolution as a result of anything that you do.  It can 
only escalate the matter, and depending upon the size of your community-- 
do be careful placing your child in those particular cross-hairs.  Word 
does get around.  Mostly that word is going to be that you're a little neurotic and overprotective.  (Unfair, I know.)
Here is what I think that you can-- legitimately-- state re: your decision to homeschool:
* attendance was not possible in the absence of a working IEP in the classroom-- the phrase that pays here is "hostile learning environment."
* your child was denied FAPE because of a procedural deficit (they didn't act to 
have a plan in place when he entered that teacher's classroom).
In other words, 
they need to fix that.  They need some more effective means of meeting their child-find obligations and getting accommodations in place earlier-- what if this were a child who was medically fragile, hmmm?   Any teacher with that attitude toward a child with asthma or diabetes could leave the district HORRIFICALLY exposed in terms of legal liability.  Point that out.
If you make this about THAT teacher-- your message will not be heard.  So don't.  Make it about the process instead.
Then-- walk away.  
