I seriously doubt that anybody would do that. Calling BS.
That said, at the supermarket, I do automatically steer myself into a check-out lane manned by a woman cashier. I don't like to have men checking my groceries. My wife finds that hilarious, just a quirk of mine. But that doesn't mean I'll leave the supermarket in the rare instance there are only men at the registers.
I avoid both. Tired of the incompetent, rude and arrogant AA cashiers hired in the supermarkets these days.
All of the supermarkets around here, save one, have self-check out lines and I head straight for those - I can check myself out faster, more competently and bag better than they can.
I noticed a lot of people using this option, more than ever before - and I'm guessing for the same reasons I use self-checkout.