How was she endangering the students? If she only expressed her beliefs, then I'm still in the free speech zone of things, and you fight what you believe are wrong ideas with the expression of your right ideas.
I honestly think that teaching girls that anyone who gets raped was "asking for it" endangers students. It prevents girls from reporting rape, thus risking health and mental health issues, not to mention leaving a rapist out there to hurt other girls. It also gives boys an "out", by allowing them to justify their actions when they rape a girl.
But then, I suppose that you could argue that my telling girls to use protection endangers their mortal soul, so I guess you have a point. But, it's still wrong of her.