Deep pockets, great reason to sue when you have a winning case and (while not a lawyer) I believe they have a winning case for multiple reasons.
1) The SPA is a contract (though there is some argument against this, I don't think a court will agree)
2) The FDA violated their own guidelines (even if they can conjure up some pseudoscientific excuse why the science changed) for breaking the SPA and cannot use paragraph D as an out.
3) That during this whole proceeding evidence of the corruption involved will surface
I thought you were implying the management was "got to" the same way the FDA has and won't file suit for that reason.