I've been out of the tennis loop for a while but had to check what's the fuzz on Djokovic. I watched the video and it seems unintentional but it was reckless of him to hit the ball that high towards an official. He could have hit it low and let the ball roll over. The disqualification is warranted.
~
This is such BS. He wasn't even angry. Have you seen the video? They have 10,000 cameras and they could find one with the ball hitting her face? come on now.
He turned around and lightly hit the ball to the back. His face was completely sincere when he saw her. Pure honest mistake. The Judge was such a drama queen with her All Star acting.
You might want to reread the rule provided by @JollyGood again. Angry or not; Honest mistake or not, the act was reckless.