Your version of her "hamming it up" has been discounted, I think. He hit her on her windpipe, with a straight shot. She went down immediately, if you watched the video, (or live, as I did,) gasping for air. That didn't look like theatrics, to me. If I thumped you on your larynx with my finger, it would hurt. It is unfortunate for Djokovic that it was a direct hit, but I'm not even sure it matters how much he hurt her. He hit her, which is against the rules.
Of course he apologized in the presser, after nearly hitting the ball kid, and did cop to the fact that it was a ball struck in anger. He's been lucky, more than once. The only thing he's seemed to learn is to be more politic about apologizing after the fact.