The obligatory link: Medal Revoked After Runner Fails Gender Test
This can really split down two separate lines, one serious, one much less so. For the first, I'm no genetics expert, so I'll leave the amount of Y chromosome in the supposed woman's genetic make-up to someone who is (or, at least, to someone with enough time to do all the necessary research!).
My initial thought, though, after reading nothing but the headline, was this: A man went to all the trouble of getting into the women's section of the 800m race, and still didn't manage to win? Now, I'll grant you, I certainly couldn't, but at the same time, I'm not training daily for olympic-level running, either. The line of thought goes something like this: "He couldn't compete with the men, so he went to all this trouble to compete with the women instead... and still failed to come out ahead." Read that way, it certainly would've made for a more interesting human interest story.