This was a smaller moment, but similar to yours, OP, in that it revealed some unconscious thinking in my head.
But I was playing Crusader Kings II quite a few years back. And I basically had a King with the Genius trait and some other stuff I could pass down to his kids. I think I had somehow lucked into the Byzantine Empire or something, so I was basically seducing and inviting a bunch of lovers with other traits from all around the world (north and south, east and west) so I could spread Genius around. I wanted a smart council full of my bastards, heh.
So my genius slut-king has a bunch of kids. I'm naming them after my absolute favorite characters from books and such, because they're part of my family and dynasty--so I'm giving them names that have a lot of personal "worth" to me.
Then I get to the kid in my dynasty who isn't white, and I couldn't figure out what name to give her. I had all these awesome names that I was using over and over through the generations in my dynasty, but somehow none that felt "right" for her. I tried and tried to choose a name, and none "fit".
And after a while, it suddenly hit me in the face how SUBTLE racism can be. This was just a video game, but I had something that was "high worth" to me to give out, these favorite character names, and I was handing them out like candy until I got to the one kid and struggled, making all sorts of excuses why this not-white video game kid couldn't get the name of this other character I really liked.
Now, if I was doing that in a frickin' video game, imagine what people are doing with REAL LIFE things that are "high worth" to them. Hiring at jobs, giving gifts and presents, selling a house, etc.
And it wasn't like I was going around in the game consciously picking which kids to screw over. (I mean, moreso than you usually do in Crusader Kings, the game where people glitch themselves into marrying their horses and creating witch covens with devil-babies so they can spread satanism across the world.) I ended up screwing this virtual kid over because I was going on this "gut feeling" that my really cool favorite-character names just somehow "weren't right" for her, even though that frickin' inbred cousin over there with a family tree like a wreath was proudly wearing it already.
So yeah. Learned a big lesson on how internal gut feelings influence you to do racist shit really subtly sometimes.