Your problem is that you can’t tell from the piece as written whether it is based on “some modicum of credible sources” or not. There are effectively four sources relied on: 1. A source “with direct knowledge of the situation.” That could be an eminently credible source. Of not. If it turned out that source was the dean for residential life, or the fraternity president off the record, those would be credible sources. 2. A source who claimed to have spoken with people at DU, and who had knowledge of unpublished details. That could possibly be a credible source, but it sure doesn’t look good. 3. Widespread rumors, reported as such. 4. The DU president’s non-denial. Also not strong, but worth taking into account. If nothing happened, most people would say, “Nothing happened!”
I agree that this doesn’t look like a piece that’s be sourced adequately to publish. But we don’t know anything about the sourcing. It could be fine, and just awkwardly described. I’m sure they thought that by not naming names or giving any details they were not publishing a “hit piece.”