TRS-I'm glad your meeting went well.
I had the experience of the educator triggering on me (!) and I had a flash of clarity that at least I was further down the road of clarity/self-awareness than she was. I thought it best to end the meeting and said I'd go over her head with it and she happily agreed! Sometimes, it is the administrators that have been through the training for these circumstances and the regular school staff have not.
It is hard to stay focused on "That was then, this is now" as well...and it is about our child, not us, even though we take it so intensly personal because we've been through that crap mill too many times and it rakes our heart to see our dc go through it. Standing up for our dc though, is in the same box as "we will treat our dc better than we were treated-ie: with respect".
Great congratulations to you for having the courage to advocate for him.
Thankfully my ds is graduating this year and he is so not going to look back. Sad, I know, but I am proud of him in his resolve that he was surrounded by crap people for so many years and he knows he doesn't need a connection with any of them.
Attila-nice quote. My ds is quite talented musically and caught alot of grief for it...even from the instructor (who is a bully himself)! 
Mampam-that is awful. It really hurts that innocent children just don't have a chance at all. Hateful world. I am sorry you had that happen to you.
TIHIF-great lyrics. Very insightful, succinct and to the point. Well done.
MH-I think Grace's advice/strategy is good. I hope you can have the experience and in the spirit of achieving at least neutrality (emotionally), can come away with:
I saw my mom. So what?
I know that on the surface that sounds dismissive. But for me, in dealing with my toxic sister, it helps build a boundary (that is a defensive negative) or rather a framework (proactive positive) for brain processing.
So what: she is not going to have a negative effect on me.
Hopefully, there will be some positive effects going on...keeping my fingers crossed for you.
Good luck.
Grace-thanks for the catepillar/butterfly development analogy a while back. It is very helpful to have a visual to attach to feelings.