The biostatistician (singular, because it is singular in the article) originally calculated the odds of the coronavirus evolving naturally to be 1 and 13 millio

The biostatistician (singular, because it is singular in the article) originally calculated the odds of the coronavirus evolving naturally to be 1 and 13 million, then, perhaps based on new information, recalculated it to be 1 and 13 billion. He was off, exactly, by a factor of 1000 between his calculations.