Hmm. It was a rather fine call as to whether that was valid for the Infield Fly rule - I mean, "ordinary effort" is probably fair, but he was a long way back, and I doubt there was much chance of engineering a double play by intentionally dropping the ball. The call was made rather late, but not sure that that really changes anything about the play, unless you're a Braves fan who suspects something underhand about it all. It only became a controversy because Kozma suddenly backed away from the ball.
The Ross homer was certainly a late call as well by the umpire, but I can't see that it should have been a K. He'd been asking for time, he eventually got it. Lohse shouldn't have thrown the same change-up, frankly.
But as you say, the Braves really ought to blame themselves rather than anyone else. Crappy defense, and not delivering when they had men on base. If they had performed at the level they have for the last month or two, then they would have won that game easily.