Re the discussion on irony...
I don't particularly like Polly's way of putting it because it strays into victim-blaming territory ("letting herself go in, drunk", "silly girl, he might attack you"...). Victim blaming is abhorrent and I think that language might have been clouding what (I think) she was trying to say.
I've thought about it and interpret it differently:
It challenges popular misconceptions about rape and risk to personal safety...
Two scenarios: one is going into a secluded space with a stranger whom you know next to nothing about, you have no reason to believe you could trust them, you're heading into a space where you can't be seen or heard. The other, you're about to share a journey home with someone you've known professionally for quite some time and feel you know and trust, you feel comfortable with them professionally and socially; they need to pop into their office for papers en route and you go with them.
Most people would perceive the risk to be in the first scenario. The second scenario feels like the "safe" one. The shock rape scene turns these assumptions on their head. Women are actually more likely to be attacked by someone they know, yet a popular misconception about rape is that it's perpetrated by strangers, down a dark alley sort of stuff.
So the irony to which Polly is referring is, I think, this: the brutal attack comes in the "safe" space and circumstances rather than the place/circumstances perceived as risky and dangerous. She's not comparing or likening consensual sex with rape.