...ingestion of fly agaric mushrooms ... a cause of this sad event.
It is abundantly clear that the hikers had become mentally deranged. They had left their shelter in the middle of the night to walk away without sufficient clothing and footwear to stay alive in subzero temperatures. Their injuries strongly suggest that they may have been experiencing psychotic episodes and fought violently amongst themselves.
Was the cause of poor Dubinina’s missing tongue for example, the result of her continuously talking, jabbering and shrieking until another group member, in the grip of his own psychotic rage, cut her tongue out to ‘shut her up’. Worse things have happened during drug fuelled violence. In any case, it is clear that the group had become massively deranged and the most likely explanation for this is the action of a chemical agent.
...
this would be the worst possible scenario as crammed up against one another in a tent at night in the middle of nowhere in winter weather would be an ideal environment for severe paranoias to arise.
Alas, hallucinogenic mushroom derangement and all other theories where several of the nine hearty victims acted physically wildly inside a cramped tent that was too short for them to stand in are disproved by that tent's orderly contents when discovered by searchers and the orderly footprints of all of them leading down to the trees. We know that they moved normally (or slowly) inside the tent and walked (not ran) down the slope for nearly an hour. The only theory that accounts for all the evidence is snow suddenly pressing down on the tent to limit movement of them and other items inside, but not enough snow to kill them. As strange as that seems, it's literally the only possibility that matches the evidence. That same evidence that disproves the mushroom/poisoning theories disproves some (but not all) of the famous Holmgren 2019 theory. It's conceivable that hallucinations occurred after they arrived at the trees, since evidence there neither disproves nor supports such. Since the evidence shows that the nine victims were the only ones in the entire area (no other people, large animals, large objects falling from the sky, etc.), they themselves (and wind and snow) must account for everything. Other theories are conceivable but are not supported by actual evidence.
The only "out" here is something so unlikely that it's almost not worth mentioning: a victim(s) in a hallucinogenic or other mental state restored the orderliness to the tent after the initial panic and then left and froze to death. That scenario is so unlikely that I have not yet figured out how to word it in the logic chain in my multi-page solution without distracting from the logic my approach depends on, but here's the wording I have so far:
"This scenario from the logic chain earlier herein has no evidence supporting it, so I dismiss it out of hand, but for completeness, here it is:
The group cut the tent and left in panic, of course knocking things around since there was barely room for nine people. The snow that searchers later found covering the tent had not collapsed on it yet. The group went down to the trees, and the katabatic freezing events there took place. Simultaneously, one or more of the group returned to the tent by following the deep footprints in the snow, still not clothed properly (or they had remained at the tent the entire time). Somehow in the dark they decided to (and were able to) spend time to restore the disordered items to their proper order (as found by searchers weeks later) instead of saving their own lives by donning boots and clothes, then left the tent before the snow collapsed (or dragged themselves out after it collapsed), and walked down toward the trees, and froze to death.Again, there's of course no evidence that this absurd scenario occurred, and I list it only for completeness, since my entire discussion follows the logic chain of which this scenario is one of the eliminated links."
[Of course I need to add the fact that the deranged person must have been the one who put Dyatlov's jacket outside the tent and who put the flashlight on top of the snow that got onto the tent, but the scenario was already so outlandish that I haven't yet figured out how to add those additional bits without it seeming even worse.]