New York State Law or no?

i am a freshman in college...a few weeks ago me and my friends were caught by an RA in a room with two 21 year old guys. both guys were of age and drinking beer. the RA wrote everyone up in the room including me and my 4 friends. me and my 4 friends had a midterm the next day so we werent drinking that night. we were just hanging out in the room . we had a meeting with the RHD and nothing was bad she just explained to us that it is a law, which i totally understand. but is minors in the presence of alcohol really a law? i mean all 5 of us are 18 and you can get into a bar at 18 and be around all the drinks aswell.