New 'Hobbit' disease link claim (BBC)

So homo floresiensis may just be a homo erectus, defectus, after all. Or not. That's not really why I'm posting this -- I'm more amused by the comment of one of the lead archaeologists, talking about the theory (of which he is unconvinced) that homo floresiensis is just a diseased homo erectus.

"Let's buy into [the sceptics'] argument just for a bit of fun," said Professor Bert Roberts of the University of Wollongong, Australia, a member of the discovery team.

"We've got a complete lower jaw that's identical to the first so there we have a situation where we've now got to have two really badly diseased individuals.

"We've got a diseased population like some sort of leper colony, living in Liang Bua 18,000 years ago. The probabilities have got to be vanishingly small."

So in other words, we can discount certain scientific hypotheses on the grounds that their probabilities are "vanishingly small". Now, what would be Prof. Roberts' justification for that position?

More to the point, does he think this is an acceptable method to apply to all hypotheses? Does it work for Darwinian evolution? Will the ID crowd be allowed to have this discussion now, or are Dawkins and chums still going to shout them down for being "unscientific"? Inquiring minds want to know.