The best thing you can do in that situation is leave. Yea it sucks but college is a place that you have to pay to be treated like a toddler. The fact that he was a cop greatly increases they "You can't win factor".
Reminds me of a story, a guy took a pic of a train, I think it was an Amtak, NYPD cop starts reading him the riot act "9/11 national security, bla bla".
It is not illegal to take a photo of an Amtrak train. The guy taking the pic showed the cop the law on his blackberry. This resulted in him being handcuffed to a post until a supervisor got there and then had him arrested.
They have not charged him with taking pics of the train, becasue they can't, it is not illegal. But he is charged with blocking access to a public area and some sort of assault of the police officer because the cop did not like they guy's tone.
This was a taxpaying citizen doing something that not only is there no law against, but there is a specific policy indicating that it is ok. In your case as a student, you can't win. If you took it to court and won on legal grounds, the college would just expel you or take some other retaliation.
It would have been awesome if PV's had been invented back when the whole county was a "designated smoking area". The only places you could not smoke were for fire safety reasons. The PV would have taken care of that in most places. Now we are all criminals not for what we are doing but for what it looks like we are doing. Never mind that smoking bans were supposed to be about 2nd hand smoke. We are a minority and are stepping out of what is considered "acceptable behavior" .
But it is not all gloom and doom. Right now you know and I know you are not breaking any law. So go to the bathroom or some private place inside and
vape your brains out.
I am reminded of another story from my younger years. I lived in a college town at the time. I bought some gas and paid for it on my Visa card. For some reason it would not read on the terminal inside (back before pay at the pump). So, horror of horrors, the attendant had to type in the CC #. After those painful seconds of back breaking typing, the clerk gruffly states. "Your card is F*&Ked up. You need to call Mommy or Daddy and have them send you a new one. I shouldn't have to type it in."
The funny thing was I not only had already graduated college and was working full time, I have been on my own since I was 17, and not only was the card my own account, at the time my parents did not even have a credit card.