Wow robbby I'm frankly amazed.
not at the behaviour of this school, (heck I could write the book on governer and teacher cover ups of abuse and bullying in school), but at your ability to dam well write a good, clearly formulated, rational and persuasive arguement, despite the fact that the issue about which your arguing is such a major one and from the sound of it, one which people would like to forget. I particularly liked your road junction analogy.
So, congrats on that score. not only are you working towards something worthwhile, but your doing it really affectively, despite how possibly triggering and emotionally charged the issue is.
I can't comment on the legal or process side of things, sinse obviously in the Uk things are different, but one thing i will say is it's pretty clear that whatever happens, you've done a dam good job in a worth while cause which, all things being equal should have a good result, and if not, that is not going to be your fault.