I’m not an attorney, but he seems to have done a reasonably good analysis and come to the conclusion that there isn’t a case for libel.
Did you read the same article?
Seems to me he makes a case that there IS a case for libel. By the fraternity as an institution and by several different individuals, most notably the probably very few male members of her small study group.
He points out that it might not be in the best interest of the person libeled to file suit, but that’s a completely separate issue.
One element that Volokh left out which would make a libel case stronger — some of the “reporter” Erdley’s comments since the publication. She actually admitted to shopping around for a good rape story to sensationalize, and settling on UVa as a target because she didn’t like the University’s realtive lack of radical left-feminist politics or their Southern culture. That indicates some malice aforethought.