Question for Nilay: Shouldn't the Mod's original authors retain the rights to the term DotA?

It has recently come to light that Blizzard is taking Valve to court over attempting to register "DotA" as a trademark. Both companies are basically claiming the term is theirs. Blizzard because DotA was a Starcraft mod and Valve because the authors are now under their employe .

What seems odd to me is that I wouldn't have thought either company would be entitled to this term. Shouldn't the mod's original authors ("IceFrog" and other people) be the people to register the trademark if anyone? (And presumably they would license the term to Valve for the creation of Dota 2, so Valve would win in practical terms in this fight, but also have to pay some royalties to them in addition to remuneration for developing Dota 2)

Is it possible that what I described is happening and Valve is just registering it on their behalf? Or could potentially one of the companies be entitled to the term? And if so why?

Story info:
http://pc.ign.com/articles/121/1218437p1.html
http://www.joystiq.com/2012/02/10/blizzard-taking-valve-to-court-over-dota-trademark/