Well, damn! It IS a deus ex machina ending! Never saw the Spenser episode, but The Closer sure fits the bill. Invent a new bad guy to get Brenda off the hook. Ethically, I think she was completely justified in what she did. Pope let that military type talk him into granting immunity to get the killer to talk. He should have held firm. If ever there's an argument for bending the rules, it's when a system of justice is misused.