Cafepress is, except for their new screen-printing services, produces their wares only on demand. Someone orders a shirt, they validate the credit card, print out a thermal transfer, put it on the shirt, and out it goes. The only "inventory" of unsold merchandise is entirely blank.
Cafepress allows people to create "stores" without any human intervention, much as Freerepublic.com allows people to post articles. If someone actually tries to order something, someone at cafepress.com would have to actually look at it (to get the transfer in the right place if nothing else), but otherwise I doubt if any human being at cafepress.com has ever looked at most of the pictures available there.
BTW, how were the prices for the shirt set, compared with cafepress.com's base prices? Did someone set this up to make a profit, or did they just use cafepress.com as a custom printing service (I've done precisely that in the past; if you're curious, click here for my 'store')? I wouldn't be surprised if it was the latter.