I actually did see that once. I was eating at a Subway at the convenience store at a gas station and a Model S pulled up to a pump, got out, went inside to the restroom, returned to his car and drove away.It does go both ways and I am sure it does happen, but in my years of supercharging, I have never seen an EV parked in front of a gas pump.
I've also seen Teslas at J-1772 stations, not plugged in.
Tesla is mainstream. That means they are owned by good people and basic jerks.
That's actually a good thing in my mind, as there will always be jerks and I'd prefer they drive electric than pollute the air.