No idea what you were exposed to, but it certainly was not an e-cig. I can use my e-cig in the car with my wife sitting right next to me. She is not bothered in the least. And she is one sensitive woman -- she suffers from just about every allergy known to man, and I suspect from a few more than aren't.
e-Cigs are disgusting and the air around them is as bad in their own way as the real things.
Maybe he/she was with someone smoking some weed.