No reason for that. I just thought he would find a way. He had those two balls that caught the outside of the line before the tie breaker to give him another chance to break Djokovic and then went a little passive again hitting the ball up the middle. Novak just played the biggest points better today.
Djokovic is like a spider in big matches. The opponent gets stuck in the web more and more as the match goes along.
Only complaint from a legendary match: The on-court mc sucks at these big events. They ask the stupidest questions.