Some informations was not disclosed. This is why this affair has remained so mysterious. Here are some suggestions:
-Assassination of an organization or a structure with can be act of torture. Each tourist had undergone different treatments.
-Crime for ecological reasons
-Discreet (or even secret) mission that has gone wrong. May be there were scientific experiments. The bodies suffered heavy compressions.
One tourist was killed or seriously injured and it was decided to kill them all, to exclude any testimony.
We only think of the mountain and the forest where the bodies were found but may be there was another place where certain things happened. For these situations, the place around 1079 was made up. The others involved had plenty of time to think about how to hide the truth before the rescue arrived.
At least, for ideological and political reasons, the official decisions satisfy the authorities. It is to admit indirectly that they did not know the truth and especially that they did not want to go further in the investigations. Digging even deeper could reveal unexpected things.
An animal can also be at the origin of the tragedy.