There really is only ever one thing to say in a situation like this, and it is "Yes, I refuse to participate any further in this farce; good day!" and then hang up. Personally I would not have been so polite :)
CoC committees are breeding grounds for idiots who think you can legislate for common sense and basic decency; and in my book that is a bridge that's worth burning every time.
I really hope the author finds some peace in all this, nobody deserves to be treated they way they have. And I hope that others who have found - and will in future find - themselves in this same situation, will have the courage to stand up to this kind of bullying by refusing to engage.