He may of never of had to rat if it wasn't for John, I believe if he was in any position to save himself though he would of so I agree. Unless he conducted business in a far more safer place than what john did. But if Sammy was boss and John was the underboss I don't think John would of ratted out Sammy. That's the only thing John had he was all about La Costra Nostra despite the mistakes he made.