I've noticed minor adjustments in statistics like this off and on through a season. I once had a pitcher (I forget who) who was 5/5 at the end of the actual regular season. A month later he showed up as 4.9/4.9. My guess is it is a minor rounding error in the calculations used to generate the statistics. Depending on when the rounding is done, being off by a 1/10th wouldn't be uncommon. Especially if they occasionally tweak how the stats are generated.