I think that the theory that some other people forced the hikers out of their tent, sabotaged it and marched them down the slope is a simple and credible explanation. The murderers may have stayed around and observed the group from a distance waiting for them to die of hypothermia, which some did. The ravine four being better dressed survived longer and stared to build a new shelter. The murderers may have then returned to finish them off. It's possible they placed the cameras on some of them after they had died to throw people off thinking it was other people. It makes sense.