I am also unhappy when someone downvotes me without comment, but in this case I think I can explain it.

Stating facts is not sexist. There is no sexism in that statement (if it's true). If you see sexism there, I am sorry to say that, but you're the one biased here.

> If a woman close to you were to suggest she were raped or coerced into sex, would your first response be "Show me the proof!"?

If I knew her, probably not, if she were a stranger, probably not the first response, but at some point, yes.