In January I used that phone number in the WhoIs info to get a hold of William Barnes. He denied having any knowledge about the shirt, apparently doing very little "ground-level" direct intervention with Nerdyshirts itself. He was receptive enough to my call, saying that he'd need all the information on the matter before proceeding, and giving me his e-mail address. I sent the following e-mail a few days later.
Covered pretty much everything, I think.
So far I've received no reply, and the shirt is still up on Nerdyshirts.com.