[skylark]

Let me preface this by saying that I am not a criminal lawyer and what I know of criminal law was from studying to pass the (not Massachusettes) bar and from watching a criminal trial that was not about rape ... If anyone more qualified reads this, please feel free to jump in with better advice!

However, the whole double jeopardy thing is at issue when the lesser offense does not have any additional elements that are separate and distinct from the more serious offense. (Example, Offense 1 requires ABC, Offense 2 requires ABCD). This may or may not be the case with sexual assault and rape -- I just don't know.

The bigger issue is ... the story just isn't very plausible because a rape charge or sexual assault charge is defined that way not by the victim (victims aren't the ones who decide what charge to bring and whether to bring it). Rather, the victim would report the facts to the police ... and then the local prosecutor would decide whether the facts constitute an assault, a rape, etc. So victim-ignorance is never really an issue. If the prosecutor bungled and prosecuted a rape as a sexual assault for whatever reason, the victim's knowledge of the law relating to rape would still have no bearing (she can't go out and get a lawyer to change the charge or anything... she has to convince the prosecutor to change his/her mind).