But I could say, I wouldn't have slept with her if she wasn't Spanish, because I specifically set out that night to nail a Spanish girl. I told my friends, "hey, you know what nationality I haven't nailed yet? Spanish. I'm not gonna sleep with anyone else until I nail a Spanish girl!" Hell, I could have written that on my blog or something, as hard, factual evidence that I was not going to sleep with anyone unless they were Spanish.
Now, if a girl lied to me and said she was Spanish, but actually she was French, do you really think that that constitutes rape??? It's completely frivolous, but according to you, I have ample evidence that I would never have slept with her had she not lied about her nationality. It's a stupid, dumb, frivolous charge that I can make on her, to accuse her of rape, and pretty much ruin her life. Now, don't give me the old crap that the judge can let her off, because he thinks I'm just some douchebag who wanted to nail a Spanish girl but instead got a dirty, stinking frog. The law is the law -- I was clearly intent on sleeping with no-one unless she was a Spaniard, and the law says that this is rape. It's moronic, and the law should (and, indeed, does) distinguish between this kind of frivolous accusation, and the more serious accusations it is intended to deal with (the cases noncon brought up earlier: someone pretending to be a gynocologist, someone pretending to be a woman's husband, etc).
But how does it deal with it? Does it say, "well, this man was clearly promiscuous, has no morals, was dressing provocatively, and rather invited the woman to rape him"? No, of course not. First, loose morals are no reason to deny someone their legal rights. Second, it sets an utterly reprehensible standard for the other, more serious rape cases. For example, I think it's fair to say that the girl in the OP is a bit of a slag, and it's quite easy to claim that, since she slept with him so easily, she doesn't care at all about his background. However, what if the man indeed lied about STDs, or some other more serious lie? Would the severity of the lie somehow outweigh her promiscuity? No; that's a dangerous and stupid path to go down - how can you weigh the severity of the crime against the moral fibre of the victim? So the law makes no mention of her moral standing, because it's reprehensible to deny people legal recourse on the basis of someone's loose morals.
Does it deal with it by saying, "well, in this case, it probably didn't ruin his life - the man is probably no more or less happy than before, and indeed, she is a beautiful lady: how can any man have suffered from being raped by such a lovely girl? I would think he would be grateful for being raped by her. Afterall, she is waaaaay out of his league." Again, reprehensible precedents, and completely arbitrary determination of the amount of suffering involved. Maybe this could fly in a civil court, where the victim claims for damages, but in a criminal court? Not a chance.
So how does it deal with it? Well, lets look at the cases it was intended to deal with again: pretending to be a gynecologist, pretending to be someone's husband... what about pretending to be a police officer and perform a cavity search? Pretending to be someone's father and give them a spanking? These are all cases where someone pretends to be someone the victim can trust - a figure of authority, in whom we place implicit trust, and with whom we allow far more intimacy than is usual. Society knows and accepts these authority figures as people we all trust -- it is their authority that the perpetrator exploits to abuse the victim. And in those professions, there are clear guidelines (laws, in fact) that set out where to draw the line. So judges only tend to rule in cases where the defendant has lied about being in a position of trust that would otherwise not have been given.
Yes, it may be wrong to lie in order to get sex, and in some cases it may be illegal. But it being illegal has much more to do with what the liar has lied about, than with what standards the victim sets for themself. When you start asking things like, "well, does the victim really care about their sexual partner's religion? Would the victim really care about their sexual partner's marital status?", you do what the law should never do, and especially in rape cases -- you put the victim on trial, and let the defendant claim she was a slut and was asking for it.
It's quite true that the law says "thou shalt lot lie to sleep with a woman", but it only means it for certain lies, not for certain women.