Mad Men and Rachel Getting Married actress Rosemarie DeWitt joined The Newsroom's second season along with Patton Oswalt last fall. Alas, that's not actually happening. DeWitt, after filming a few scenes, had to depart the HBO series when production shifted schedule. She was set to play Rebecca Halliday, a lawyer defending Will McAvoy's Atlantis Cable News channel in a big wrongful-termination lawsuit. The role's being recast.