Ignorance is Bliss...It's also Assuming...And then there are those that see themselves as the enforcers. "Oh my, someone's breaking the rules; I must complain even though I don't know what I'm talking about."
Kind of reminds me of smoking a Passion Flower cig in a restaurant when I was a teenager.

All the staff came and dumped the ashtrays and disappeared to the back looking for the roach. I had a blast with those things. Smelled just like pot!
All you can do is suck it yup and not argue. It is their place of venue, your exhaust does look like smoke...Think of the problems you could cause when uninformed - ignorant smokers see you getting away with "smoking" (even though you're Vaping).
