One of the articles linked above (BBC) indicates that the earlier identification was based more on dental records than DNA evidence. I'm not an expert in DNA testing, but I'd assume like all science there's a fair amount of interpretation of the data. The DNA machine won't produce names and addresses. The DNA, for example, may have indicated a 70% match with the first child's relatives, and now registers as a 85% match with the second child's relatives.
EDIT:
Just realized that I'm responding to a post from two Decembers ago.
