I think it would be hard to make a law that recognizes the difference between a failed prosecution and an obviously fraudulent accusation.
But yeah. If she was actually raped, ABSOLUTELY let her accuse her rapist. But if she wasn't actually raped and claims she was, hold her accountable for that false report.
Is anyone else remembering the big Duke University case from a while back? Buncha frat boy athlete types. Stripper accuses them all of rape. Big stink all over the news. Turns out not only had THEY not done it, but she hadn't been raped at all.
That kind should be prosecuted for a false report.
One like the Steubenville(?) case where not only did it really happen, but everybody knew it happened, there was photographic evidence that it happened, and the offenders didn't really even try to hide that they'd done it. Then the whole town turns on the victim and anyone who helped her get her story out. It's bad enough that she got no justice. But to pursue her afterwards because the local town doesn't want to hurt their high school athlete's futures would be an atrocity on MANY levels.