When I tell this story, I can't help but think back to a conversation from a few months prior to that interview. Our company was split into onsite and remote halves; the team in the field was hired based on referrals, a rigorous technical exam, and - as far as I know - phone interviews. One day, everyone came onsite for an all-company meeting, our first one ever. A few hours into the day one of my remote colleagues - who was Black, like a number of those on the visiting team - pulled me aside while he was walking through the office and asked me what the diversity was all about. I didn't really get it, but when I looked around I saw what he saw - it was me, him, and a lot of other white people that I saw every day. I laughed because I knew what he meant, but it took me much longer before I got it.
Footnotes
1. The writing sample
As I remember it, when the interviews finished I would sit down with the candidate and explain the writing assignment, which was basically a reflection on the interview and an opportunity to add anything we hadn't covered during the conversation. I stand by it and look forward to using the tactic again in the future, but I need to make it clear to anyone involved in the decision that if the writing skills demonstrated in the cover letter don't strike a candidate from consideration, the final writing sample doesn't get veto power.