They used a very cool way to analyze the Bones. Instead of chopping off samples the bones were put in a plasic Box and a tiny static upbild was enough to kick some molecules out of them which they analyzed and identified the species.
That's about the gist of this article. Cool new bone sampling tech and an obvious assumption.
Sorry but that was a bit anti-climactic to me. :)
I'm not sure I would jump to the same conclusions, though. Although reindeer bone tools weren't found, maybe that doesn't mean that they weren't made, just that the artifacts didn't survive as well.