If you're under 18, then yes, that would be true. The problem with your argument is that most college students are not legal minors.
If your in their house it makes no difference how old you are. You have no expectation of privacy. Especially since due to our draconian drug laws their house could be subject to asset seizure.

And I am sure that the lease or agreement that you or your parents signed to allow you to live in the dorm has a clause in it about illegal activity. Which also means that the RA would have been within his rights to confiscate a six pack of beer if you were under 21.

My solution was to move off campus.