Correct me if I'm wrong and if I don't understand finance or all the quirks in the law, but
one can not retire from an ownership interest. A person sells an ownership interest. Mitt Romney was the sole shareholder of Bain. When he left, he delegated authority but not responsibility to a management committee. Under the law, one may delegate all the authority he or she wishes. What can not be delegated is the responsibility. Thus, if suit were brought against the members of Bain in their individual capacities, for whatever reason, Romney would be included and responsible for all damages. I don't think there is any question.
Moreover, as Romney spent two and a half years doing the Olympic thing, he was not negotiating a retirement package. He was negotiating a sale of his interest. If he were an employee and left, his package would be in place. There would be little or nothing to negotiate. It took two and a half years to negotiate his departure because Romney had something to sell and he got big money from that sale. It was complex because he now has a stake in Bain for the rest of his life. He also has a stake in myriad partnerships, etc. Those are terms of a sale, not a retirement. While he was negotiating that sale, he was still the owner. Still responsible.