"A recent decision involving a suit over investment actions of a defined benefit plan illustrates one of the reasons why participants in a DB plan cannot sue plan actuaries for mistakes -- the participants have almost never been damaged. DB plan participants have a right to a fixed set of benefits, and how well the plan does on its investments or meeting its actuarial assumptions does not increase or decrease that set of benefits[.]" [Palmason v. Weyerhauser, No. C11-0695RSL (W.D. Wa. Aug. 23, 2013)]