In reality, the majority of destructive rumors take the form of "Bob was impossible to work with", not "Bob sexually assaulted Avery". Meanwhile: a bogus accusation of rape is far more actionable than a bogus accusation of being an asshole; if you actually worked with Bob at all, you probably can't be sued for that at all, since things that can be construed as opinions cannot be the basis of a valid defamation claim. Unlike sexual assault, which, as a crime, is probably defamatory per se.

So relative to the set of all possible destruct rumors, allegations of sexual assault stand as outliers for how uniquely protected the accused actually are.