A logical break down of key events in the DPI
Assumption: The scene has not been tampered with and accurately reflects the events of that night.
Facts/analysis
1. The hikers left their camp site, leaving their boots, their warm weather gear, and many items of equipment that could have been used as a weapon. Some of them took their cameras.
Why did the hikers leave their camp site?
A: there was some external event outside of their influence that presented them with an immediate and significant threat to their lives.
B: they were forced to leave the tent and the camp site by other people.
For either of the above possibilities it is clear that the group as a whole were not anticipating any kind of threat to their lives for either scenario A or scenario B. if they had been anticipating something then they would have prepared themselves better. They would have been ready to leave their tent and or they would have collected equipment that could have been used as a weapon ( knives or ice axes etc). Whatever happened it was a surprise.
For option B if they were forced to leave the tent by a person or persons, then it would have to have been someone or some people from within the group itself as there were no other foot prints in or around the camp site.
2. The group made their way down the slope toward the cedar tree. They were not adequately prepared for this.
Some or all of the group made it to the cedar tree, where they gathered fire wood and made a fire in an attempt to keep warm. There is evidence that they climbed the cedar tree up to a height of 5 metres. If they were marched down to the cedar tree under duress, why would their attackers allow them to make a fire to survive? This wouldn't make any logical sense, unless their attackers didn't accompany them down the slope, but instead stayed at the camp site, or their attackers being a part of the group were also exposed to the cold and made some of the other group members build the fire. But why would the attackers leave the camp site unprepared. This wouldn't make logical sense, so it is likely that if they were attacked the attackers stayed at the tent area. Another possibility is that those who were better dressed were the attackers, but almost all of the group lacked adequate cold weather gear. So if they were attacked, the attackers may have not followed the hikers down the slope to the cedar tree. The hikers could then build the fire and observe the camp site from the tree ( depending on visibility). So if the attackers stayed at the camp site, then where are their foot prints. Maybe it was the three found dead on the slope between the camp site and the cedar tree? But why would they have left the campsite without boots and adequate clothing. Nope. There is another possibility. Someone in the group had a less than 100% morale constitution. The diaries speak of an incident on the train with an alcoholic who accused the group stealing his vodka. Maybe one of the group did? Also, the guys promised not to smoke on the trip, and apart from one packet of cigarettes no other smokes were found. Nicotine craving on a survival expedition is not a good combination. There were also underlying tensions as some of the group had broken the rules and were sitting by the fire before all the jobs were complete. Not repairing the tent holes when needed. The diaries speak of the guys being "outraged" by this. Underlying tensions around tent repairs, no cigarettes, and cold night on the mountain. Maybe someone thought it was a good idea to crack open the stolen vodka and have a few warming gulps, or maybe a bit more than a few. Fuelled by a lack of nicotine, too much alcohol and underlying tensions, maybe some words were said, and then some more, and maybe it got out of hand. In a fit of rage the intoxicated person grabbed a knife and slashed at tent shouting fix this, or words to that effect. A fight then breaks out. The tent is ruined and their only means of shelter. The situation escalates and the fighting becomes serious. The group know their lives are now in danger. The person responsible now fears for his own safety as he has put the rest of the groups lives at risk. He grabs a knife and one of the other group members and holds them hostage, threatening to kill them. He orders them to vacate the area and march down the slope. They all march down. Eventually the attacker succumbs to the cold and the rest of the group take back control. The problem with this is none of the group had alcohol in their systems and even if such events could have happened without alcohol consumption, it wouldn't explain why the attacker would not get his warm weather gear and boots.
The above scenario is highly unlikely. It is unlikely that any of the hikers, assuming they were of sound mind would create such a situation, and leave the camp site unprepared. This would mean that if they were attacked it would probably have to have been by outsiders. But if this happened then they would have had to be really good at leaving no evidence or clues that they were there, and why would the hikers have their cameras on their bodies without attempting to photograph their attackers. There are a lot of problems with the idea that they were attacked, by either someone within the group or outsiders. This makes scenario B highly improbable.
That mean option A is a more probable scenario. Something significant happened that was outside of their influence. Some natural or man made event that made them panic and believe that their lives were in danger if they did not move away from the camp site as quickly as possible. This scenario does require any complex explanations. They rapidly put distance between themselves and tent/camp site. Their next best chance of survival was to make a fire which they did as soon as they found some fire wood at the tree line. The fire was not sufficient to keep them warm and the snow not deep enough to build a snow shelter. So they needed to relocate. It's not clear whether the three on the slope died going back to the tent or on their way to the cedar tree. They have though it would be better to return to the tent and died on the way. The rav 4 may have been waiting by the fire for their return or they may have gone further into the woods to look for more shelter and a place to build a snow den. If it was dark, and they were already weak and fighting the cold, it's possible they all stumbled into the ravine and fell sustaining the injuries discovered on 3 of the rav 4. The remaining surviving member of the rav 4 tries to build a shelter and drag his dying or dead friends into the den, but he dies of the cold before he can them into the den. The missing eyes and tongue are just natural decay.
Obviously all of the above is open to discussion.