He has said he did nothing wrong and that it was investigated 20 years ago and found baseless.
It's not Herman Cain's job to provide details -- it's the accuser's, and the accuser(s) simply hide behind some legal language to avoid having to answer any questions.
Until any evidence emerges to support the charge, I'm inclined to believe that nothing happened and that this is the same kind of political witch-hunt as in the Clarence Thomas matter.
The NRA of which Cain was CEO chose to settle the claims of SH for money. It doesn’t prove he did anything but it does make the electorate curious about the charges. That curiosity will not be satisfied with “I didn’t do anything, end of story.”