"Alive"

Have you ever seen the movie "Alive" or read the the book of the same title? The true story about a group of South American soccer players, in high school, whose plane crashed in the Andes, high high up, and because of storms and other circumstances their plane wasn't found? But there were survivors? And how those survivors turned to cannibalism in order to survive? 

The survivors entered an agreement to consume each other upon death, that it was the only way any of them would survive. It was for the common good--they did not say "Kill me and eat me"-- some had died in the crash, others slowly or quickly afterwards depending upon afflictions. Clearly they had made some sort of contract, and their act was also to instill the greatest amount of happiness--in this case, the ability to live on and be happy elsewhere. 

Now, the question remains how cultural relativism would see the situation. Their culture said not to eat human beings, and the cultures morals are to be accepted---there is no outside right or wrong. Their act of cannibalism was against their culture and thus immoral. Unless, that is, they became their own culture. 

When does a group, separated from its origins become its own culture, its own society, and thus bound by its own moral code? Or is that even a possibility--is the real matter that whatever code you grew up with, were raised with and lived with most of your life is the moral code that is 'right'. What about those who change countries---are they then expected to abide by, and believe the new country's moral code or else be deemed criminal or immoral? 

Cultural relativism, could relatively say: whatever you think is right is, so long as it fits what the majority thinks too. Cultural relativism could say that it is relatively moral to eat human flesh if you think it is wherever you're from. And if a visitor comes to our country it's relatively moral for us to kill and eat that visitor. In our land, our morals are, after all, morally right. 

In the case of "Alive" moral relativism provides no answer---we must tolerate it, they are not any more correct or wrong than any other culture---but then, cultural relativism offers no explanation of how to decide what counts as a culture, what the groupings should be. 

Should everything be split up by language or geographic boundaries? Or religion? Please note I choose those separations as they have been connected to wars---Germany wanted unification and so went to war with it's neighbors trying to consume all German-speaking land into their nation, a long time ago. Geographic boundaries and religion are critically important issues in the Middle East. Where do we decide where cultures begin and end, and thus where a different moral code begins and ends?

Out in the middle of the Andes were the survivors of  "Alive"  their own group, and thus acting in a moral manner according to cultural relativism, or where they immoral to eat human flesh in order to survive?