BOSTON — Kevin Durant missed 15 shots and turned the ball over six times in the Nets’ Game 1 loss to the Celtics on Sunday. But the Nets only lost by one on a broken-play, buzzer-beating game-winner from Jayson Tatum. As a result, it’s difficult to strike a balance: Yes, the Nets had some glaring shortcomings in Sunday’s loss. The Celtics bullied them with physicality on the defensive end and won the rebound margin by 13. But Durant, revered as one of basketball’s great equalizers, had an uncharacteristically poor game by his own measure. “I know what I did. I wish I had played better,” he sai…