Well I think your money manager had a case for him winning since a share buyback is designed to return value to the shareholder and ACAS has been doing this for years now. Also ACAS did give, in hind sight, a HUGE one time dividend in 2009.
You're wrong, his money manager has no case. AIG gives shareholders cash, ACAS gives employees stock. I believe the reason ACAS trades so far below nav is because investors distrust ACAS management. Two weeks after saying the div was safe they stopped it, Wilkus got made whole on his stock, the stock buyback has gone to stock options, and the 2009 stock div was forced on the management (either they paid a huge tax bill or issued a stock div), and the last time investors believed in the nav value by management it dropped from 40 bucks to 7. They have done nothing for the shareowners that I know of since 2007; they have only been protecting their jobs and lining their pockets at the shareholders expense, of course IMO.