There are some general observations I'd like to make:
1) In disasters like this, human fault is usually the cause.
A) I think a fight occurred outside the tent, probably between Dyatlov and the army veteran (older guy, stranger to the group), which turned extremely violent, using ice picks, etc. This could account for head trauma suffered by one member.
B) If you read what is known of the veteran, he experienced some intense stuff during WW2. A combInation of PTSD, and the indignation of following a kid who lost his way became expressed in a rage. They were all tired, lost, and anxious.
C) It's easy for me to imagine the 2 men running around the tent, perhaps with another member trying to intervene, shouting threats and cursing. In the darkness and ice, they fell onto the tent, which caused the members inside to cut their way out of the tent. Some made their way downhill where they had previously seen forest before nightfall. They made sure to take matches to make a fire to keep warm, thinking they would return either later that night, or in the morning. I think there were 2 groups; one led by Dyatlov which went first, then a 2nd group of 3 or 4 who stayed behind to calm the raging vet.
D) The first group arrived at the cedar and could not find dry wood on the ground, so they climbed trees to break off dry branches. Cedars, like junipers are potential life-savers in this regard. Eventually, they could not sustain the effort of obtaining fuel, and one-by-one they began to freeze.
E) Meanwhile, the 2nd group made their way toward the light of the fire. They had calmed the veteran, and meant to coax back the others. When they arrived, they were overcome with the disaster unfolding.
F) The survivors stripped the clothes of the dead. Half determined that they would take those who could not move to the ravine, where they failed to make a fire an ice cave, and an insulating mat from branches. They all froze to death. The other half tried to make it back to the tent to bring back life-saving means...they froze to death as well.
2) The injuries:
A) Chest and rib injuries were caused by chest compressions during CPR attempts.
B) Bloody teeth and lips were caused by mouth-to-mouth attempts at CPR.
C) Missing eyes, tongue, and lips were caused by scavanging birds or mammals, or perhaps water.
D) Burns were caused by simply trying to feel the warmth of the fire through freezing tissue. In desperation, they got too close, not being able to feel they were burning themselves.
E) There were injuries to extremities consistent with climbing trees.
A) The role of the veteran cannot be overestimated; he was the one not on the same wavelength as the others.
B) Photos taken from the cameras suggest who befriended, and formed a clique with the veteran.
C) Moonrise did not occur until much later in the night...it was pitch dark. This is why the notion of them climbing trees to see their surroundings makes no sense.
D) You can source Russian videos on youtube, recreating the journey from the tent to the cedar under similar snow and temperature conditions (during daylight). Socks stayed dry, and even with marginal clothes, they made the walk relatively easily and comfortably. Without adequate fire, though, the Dyatlov group were doomed.
E) Much of my theory is informed by my extensive time trekking in the wilderness. I have been too hot, too cold, too wet, out of food and water, and very lucky. Things can turn badly very quickly.
F) I realize I haven"t commented on every perceived anomaly, but nothing really stood out as inexplicable.
G) The exact causes and motivations will never be known.
I agree with the premise that simplest is best. Logic, probability and reason, matched to the known circumstantial evidence, and the precedence of the deaths of other humans in subzero temperatures. Put all that in the computer and see what it finds, rather than introducing fanciful theories of aliens, yetis and so on for which there has never been any empirical evidence, or even clear photo's in a world which now has 2 billion camera phones.
There was certainly potential conflict in the group, Lyuda seemed to be suffering from depression and wasn't pulling her weight, and there was a complicated tryst of ex love/hoping for reunion between Yuri D and Zina, and Igor who showed no body language bond with her in any of the hiking photo's yet still carried her photo in his notebook, and both men will have witnessed how both women were all over the engaging geologist Yuri Yudin when he left, so it must have been complicated, the sleeping arrangements, in that cosy tent.
I completely agree that the flail chests were likely due to resus compressions, since they are not random enough to be the result of an accident or assault. Both Lyuda and Semyon's right sides had 4 + 4 fractures to the same ribs, the very ones non-randomly fractured in resus. Break the sternal area and continue with compressions and the stress will radiate out to where the rib bends at the sides and break it there too.
The only difference between the two was Lyuda also had a single set of 6 (bilateral) fractures down her left side. Where a person only has side fractures it's usually due to a fall, central ones alone due to impact or pressure. So two events likely caused her injuries.
Any theory has to tick every box or it's 'leaky'. The idea of a fight at the tent, or even someone falling through the canvas, all these variables, sounds fine, but it does not explain why they left without what they needed to survive, not just clothing and footwear in some cases, but none of the 9 people thought to take one of the 4 axes when planning to head to woods and start a fire. That single omission killed them all.
If the knuckle injuries were due to a fight whose faces did they connect with, where are the injuries, there's some scuffs and grazed cheeks on the autopsies for some, but nothing really substantial enough to correspond to 7 damaged fists, no swollen eyes, bust lips and eyebrows. Was the pint-sized Zina really a young Rosa Klebb character, fighting like a man, and were 3 of them throwing punches equally with both hands?
Tellingly the final 3 on the pass were the only ones with the knuckle injuries to both hands. Yuri K had injuries to one hand. Nobody else had knuckle injuries. An alternative explanation, in a fight with Mother Nature
, is the final 3 would inevitably be crawling up the pass at the end. Imagine continually plunging your fingers into something that is either very hot or very cold, but you must travel across. You'd either clench your fists or perhaps walk on the 'heels' of your palms, in this case to avoid frostbite after you feel your fingers starting to go numb. Likewise Igor had injuries to his knees, unique to him, but he had no shoes, so might move at times on his knees to protect his numbing toes.
No point returning to the tent if you have frostbite to your digits, you're not opening food to eat, you're not repairing the tent, you're not packing things away, you're not cutting wood to make it through the next night, you're only delaying your demise.
We know from the skin in his mouth that Yuri K bit into his hand, which likely would be to stay awake, when slipping towards hypothermic coma. His body would shut down blood supply to his extremities, to the nerve endings in his hand, explaining why they go numb with cold, so he didn't feel it. His knuckle injury may have been if he struck something to try to jolt himself awake, especially if Yuri D died before him and he witnessed that.