Though you (and others) can't quite bring yourselves to say it, what you really are suggesting is a system of "Presumed guilty until proven innocent".

Note also that there are already quite a few laws and procedures in place when it comes to sexual assault cases. 

Crimes where there are no witnesses other than the two people involved and which could be legal or illegal depending on the preferences of one of those parties are difficult to investigate. 

Perhaps there ought to be an "accused registry" where it is noted if a male is accused, but not convicted of sexual assault. If there are a number of complaints, then that would suggest something is going on.