Hey, firehouse (and others),
I can't ay for sure exactly what happened, but there are a few more details in a news report at
http://www.channeloklahoma.com/news/3874394/detail.html
That report says paramedics responded to a 4 a.m. call and found the guy in a dorm room. He was reportedly "barely conscious" and he was rushed off for medical attention because he was "dry heaving and urinating on himself." So it sounds like more than just an instance of someone who had been drinking -- somebody called the paramedics, and near-unconsciousness and loss of bladder control aren't good signs.
The report does say that members of the fraternity did not see anything to raise concern when he left their party.
I expect there will be more info as time passes, but I can't say whether we'll ever know the entire set of facts.