Obviously this is a good rule.
About that whole disgusting "he said, she said" canard:
1) You do realize that false accusations are really really rare, and that unreported assaults are orders of magnitude more common, no?
2) Eyewitness testimony is admissible in a court of law, why do we seem to be so uniquely skeptical of it when it comes from rape/assault victims?
The problem with rape cases is that in any many cases the only eyewitness will be the victim herself. I'm not saying there are tons of false rape accusations, but you can't convict when the only evidence is eyewitness testimony from the person who's making the accusation.