We must keep in mind that if the besmirchers had hard evidence they would instantly employ it and destroy Cain once and for all. They are using the oblique lines of attack because they (a) don't have anything else (so far) and (b) they fear this man greatly.
If this is all that there is to the "scandal" than IMHO I'll quote Joe Walsh and say "So What?".
Than=then....Doh!