Indeed. In a thread a couple of days back on a different (though related) subject I was accused of being a rape apologist because I was insistent on the presumption of innocence and the beyond-reasonable-doubt standards that need to be overcome when accusations like this are slung. But it works the same in the other direction too - we can't assume that an accuser is guilty of fraud or libel or filing false reports or whatever just because they failed to prove their case.
It would not be good for justice if these situations ended up being "now that the accusation has been made someone is going to go to jail, either the accused or the accuser." The Thunderdome is not a good model to emulate.