Timeliness is important. As a matter of fact, mosaic law (on which English and then American common law is based) states that if a rape is claimed, the woman must scream for help, her clothes must be torn, it must be clear that she has fought the best she can. Further, the claim must be made immediately. If these two tests are not met, then it is assumed that the act was concensual — if it happened at all.
The whole thing is nonsense. It is too bad that when she made this claim in her book years ago, instead of just publicly denying it, he should have sued her for defamation.
The lesson here for any man (or woman as the case may be) is to bring legal action immediately if someone claims to have been intimate. On the other hand, if you have been assaulted, go to the ER immediately, and have a rape kit done.
Insane.