Yea, a college freshman in September, probably one of his first really drunk nights. Likely had a bunch of older, more experienced drinkers edging him on too. Part of college is learning your limits, and hopefully your roommate now has an upper bound that he'll never cross again. Calling the paramedics might have been a little too far, but I suppose you can never be too careful. You did do the right thing, looking for help from someone more experienced and with authority. At the very least, you legally shifted responsibility away from yourself, and at best, you may have saved your roommate's life. But that's for the doctor to say, not me.
Just remember, always put them to sleep on their stomachs, so they don't drown in their own vomit. Trying to get them to vomit in the toilet before going to bed is a much better solution, though(vomit leaves a terrible stench on the sheets). Have them drink a bit of water after vomiting, and a cracker or two can also help. Know that they might not be able to respond coherently to your questions, but keep up positive narratives anyhow ("you're gonna be alright, everything's gonna be fine"). It gets them in a more relaxed mood and ready for a deep, deep sleep.
Finally, remember that if you help a guy out when he's hammered, he'll probably help you out if the situations are reversed. Welcome to College!
As to the other conversation, I've lived with a guy who only got terribly drunk and never touched drugs, a guy who only got high and never touched alcohol, and a guy who loved both to great excess(yay random room assignments). It's all personal preference, and one certainly does not imply the other.