Cheaper to keep him?

Peter Rost, the would-be whistleblower who remained on the Pfizer payroll without any duties for a couple years while pursuing a false claims action against the company, was finally fired recently after the government declined to join his suit. He's now filed suit against Pfizer alleging wrongful termination and retaliation against whistleblowers. Maybe they should have just let him keep "working." I honestly don't know the merits of the case but it's a strange situation to say the least.