The backpack of one of the hikers was found but not the backpacker. Have I got that right?

A PSK is not much use in your backpack if you have lost it. This person went to all the effort to carry a PSK but didn't have the knowledge to carry it on the person.

This is one thing i regally come across. People know to carry some sort of survival equipment. They don't understand how to carry it or use it. It is the same mentality as people that drive around with a spear wheel in their car yet don't know how to remove it and replace the damaged wheel.