UnitedHealth Group announced a dramatic leadership shakeup, with former CEO and current chairman Stephen Hemsley stepping back into the top job following the abrupt resignation of Andrew Witty.The move comes at a time of escalating crises for the healthcare giant — including the recent fatal shooting of Brian Thompson, the CEO of UnitedHealthcare, UnitedHealth’s insurance subsidiary.Witty, who led UnitedHealth since 2021, is stepping down effective immediately for “personal reasons,” the company said Monday ...