Has this ever actually happened? I admit I don't read the news regularly, but I don't think I've ever heard of anything like this happening.

I never got this issue people had. Women's bathrooms are all in stalls. A person can't look in on someone using the bathroom in there without being blatantly obvious in which case something will be done. The likelihood of someone having that happen to them in a public bathroom is just as likely now as if they let trans people into bathrooms. It's not like they have guards outside every Women's room doing Clit-checks.