Her conviction should be overturned, anyway. Andrea Yates' conviction was overturned by a much less relevant lie on the stand. An FBI agent lied on the stand in her case.
The lie, if you want to call it that, had to do with the other guys case, not hers.
And it was a misrepresentation that a test was performed personally, when it was apparently mostly done by another lab assistant. He was just taking full responsibility for the test and the legal beagles caught the error and made it into a hill of beans.