If he's the head of a Church operating in any country, he can be called upon to testify in that country's courts. If the bishops say that they are doing what they are told and the Cardinals say that they are doing what they are told, then no one else can be held accountable other than the man in charge. Yes, I'm sure they would invoke diplomatic immunity, but if the church thumbed its nose at enough angry countries, those countries have ways to make the church pay for it. Do these abuses not happen inside the Vatican as well? I guess we will never know since they aren't likely to police themselves. Their history shows that they do not do this.