We'll never know what would have happened if Ross doesn't lose his concentration there. Medlen is the kind of pitcher that gives the Nats fits. The Nats hunt fastballs and he didn't throw many.
The pressure was greater on the Braves to win the game than the Nationals and with Medlen's stuff with the pressure of a 0-0 game building. it would have only taken a little less control on a few pitches to give the Nationals the lead. Again, assuming we get a clean game from the Nationals.