IRMS Positive but Low, Says Landis' Doc
This, from the NYTimes:
Landis said last week that he was expecting the worst because backup samples, or B samples, almost always confirm the initial result. But [Landis's doctor, Brent] Kay said the B sample could come back negative.
“The carbon isotope was only mildly elevated,” he said. “We know, from a statistical standpoint, that the first result could have been a false positive.”