> How am I "in his face"?
Because this poor guy's telling us, "I can't take this anymore," that his volunteering experience was so damn combative and miserable that he quit, and he just wants peace..
And now here you are saying "yeah? well what STANDARDS does he propose by which we can evaluate the VALIDITY OF THE BULLYING?!?" and ... like, come on. It's combative, it's insensitive, and it's an altogether inappropriate demand — you don't get to expect a treatise in the "bullying was too bad, so I quit" letter, even by way of hyperlink.
In short, by embodying the problem that made him quit and applying that problem to his quitting.