I recall a picture once posted to a thread that would meet those exact conditions, and it turned out to be a professional tour racer, but not during a race. Just cycling through town on a very fancy road bike with a backpack. I assume in the drops, and don't remember smiling.
I can't remember who it was, but I remember somebody's response comment was something like "that guy is commuting on a race bike, because it's <name>, commuting to his job as a professional bicycle racer"