Is Sexism Really To Blame For Serena Williams’ Penalties?

Serena Williams broke the rules and was penalized for it but she says that men get away with breaking the rules all the time. Following the match she decried what she says is sexism and many agree. However when I look into archives I can see that Serena has a history of bad behavior, men do get penalized, and so do other women. Why would this incident be worse than others? Is this an incident of unreasonable feminist "social just warriors" in action or a just and honorable call out of bigoted behavior from the ump? Sexism in Tennis does exist and we have even seen recent examples, but is it fair to say this incident was the same?