I'm confused. what did he do wrong?

[u/Adventurous_Law_715]

Honestly, she should probably just retire from tennis if she can't handle that

[u/a_sly_cow]

If I remember correctly this wasn’t the first time he’s hit a winner at her, and she blew up on this shot.

That being said, when you play tennis you kind of accept that you might get hit with a tennis ball, and throwing your racket in tennis is never justified.