But once any adult reaches outside the culture for help (or is unable, for ANY reason, to say it's ok and part of my culture) - then any legal protection is gone and the legal (or whichever) system takes over as it would for any citizen.

So if you murder someone... they are unable to tell the legal system that it was ok in their culture (Because they are dead) so the courts take over.

Basically it gives the choice of staying in that culture to every individual, until that choice is taken away from you. I left it that broad because I wanted to include more than just murder, like a coma or a serious mental illness that prevents the "victim" from communicating