So what went wrong? I think that will have to await sight of the judgment, which doesn't appear to be on the web just yet, but the Brief on the Motion to Dismiss (which I am pleased to see was co-drafted by my friend Marc Randazza) gives us a good clue: the assignment, such as it was, gave Righthaven no rights to use the copyright works, just to sue for infringement. The rights were assigned "solely to coat its lawsuits with the veneer of legitimacy" - nice turn of phrase there. Here is the Strategic Alliance Agreement (see clause 7 in particular).
The excellent Electronic Frontier Foundation filed an amicus brief in the case and have more information about it here.
Wolf is one of over 50 cases brought by Righthaven in the Colorado court, so from their point of view a lot hangs on it.