CPS guidance on evidence requirements for rape prosecutions: "The police will always look for corroboration or supporting evidence (such as medical or scientific evidence, CCTV evidence, or eyewitnesses to events prior to or after the incident) but it is not essential and a prosecution can still go ahead without it."
Anyway, how would such a case be relevant to this? There is solid evidence of events before and after that strongly support her version of what happened and lots of stuff that casts doubt on his truthfulness, it's not purely her word against his.
Of course it could go one way or the other, but I think you and a few others seem to be misinterpreting the level of evidence needed to be 'beyond reasonable doubt'.
Hers too