Is AUTHOR wrong in the post ? POST : Before you say "of course NTA" I might be in the wrong. 

So I go to a college campus where they really don't want people drinking because it's caused a few incidents. They come up with events on the weekends to stop people from partying and I've been lucky enough to be chosen to host one of these events. Now this is a big event with almost 400+ and huge monetary prizes and one of my friends (let's call them W) comes a lot. 

W drinks a lot. He's a casual alcoholic to say the least. He brings in alcohol everyday and his excuse is "I'm not getting drunk and it's only 8%! It's not so bad"

Now at this event, it's specifically to stop you from drinking. The event I'm helping host is being co run with our campus's center that helps people with alcoholism, addiction, sexual issues, mental health, e.t.c. 

This type of event was run about 2 weeks ago and I saw W bring in a can of alcoholic cider and everyone in our friend group told him to put it away or throw it out. He chugged the whole thing and threw it out. Now I'm afraid he'll bring in drinks to this event as well and some of the following will happen: 
The organization co hosting won't do it again because their events are specifically supposed to be dry and safe. 
He'll be barred from future weekend events. 
He'll get in trouble along with anyone vouching for him. 
I'll get in trouble if it's found out I knew this was going to happen.

I tried to convince him to stop and he's really a nice guy but I'm getting frustrated with the excuses between "I'll just pregane" to "I'll stop starting now" to "No one will notice! You'll be fiiiiine." It got to the point where I took his bottle of alcohol and wanted to flush it down the toilet because it feels like he's being plainly disrespectful to me. It got to the point where I ran into the girls room so he couldn't follow, but he did and crawled onto the floor for a $3 bottle of beer. I know that was harsh but wouldnt that be a sign of an alcoholic? (I wasnt actually gonna flush it though. I don't really have the heart to and I know this shouldn't be my problem but I feel conflicted) 