"but we know empirically that people who come in dressed in suits rarely work out well for our team." Really? You keep metrics with clothing formality on the x-axis and success on the y? Otherwise all you are doing is shoving the word 'empirically' into a sentence to try to disguise your confirmation bias.
In addition to the love being given here, I'd like to throw in that if you are updating an existing web app, nothing beats KO. You can add it incrementally to a page without turning your whole app upside down.
You can do just about anything you want, it's the way you do it that matters. You went over the line when you publicly posted their photo, plain and simple.
And your defense of possible misunderstanding is, to be blunt, far short of logical. You don't know that he didn't defend himself to the organizers and that they rejected his defense (unless I've missed something).