US Open's sexist code violation umpire put firmly in his place

It seems kind of ridiculous that, in this day and age, female tennis players can be given a code violation for changing their shirts on court. And, indeed, when Frenchwoman Alize Cornet did so at the US Open this week, after realizing she had her top on back-to-front after a change during a heat break, there was a great outcry of "sexism!" The competition's management later issued a public clarification to the effect that the code violation decision was wrong and that women are in fact allowed to change their shirts on court, just the same as men are. The World Tennis Association also slammed the decision, saying that changing shirts on court is not against any WTA rules as there ARE no rules on that, either for men or for women.
So, in the end, no fine was levied, and Ms. Cornet went on to win the match. However, it still begs the question of what the chair umpire - let's name hin: Christian Rask of Denmark - was thinking in issuing a code violation in the first place. Shouldn't HE be issued a fine?