I was thinking of the possibility of dropping a string on thermobaric air mines of some kind.
Don't do it Star man, there's no need to go to such extremes just to prove a theory. Theory #236, Variation 5....
The hikers are in the forest, or up on that ridge after all.
A helicopter appears, or a plane, it's either a military manoeuvre connected to the other soldiers in the area, who became distant witnesses, or the hikers are mistaken for escapees in the dark.
If a test, they choose the Dyatlov Pass to target, because they know the Mansi don't use it, wildlife avoids it, and don't anticipate anyone else will be there. Or they are out looking for escapees and mistake the hikers for them in the dark.
Air mines/grenades are dropped on parachutes, they are thermobaric types.
None of the hikers are killed outright, there is no dismemberment/fatal blood losses, but some have burns, fractures and head injuries, and the wider problem becomes a delayed issue with their lungs, due to the thermobaric weapon interrupting the air space in their lungs, which slowly fill with fluid due to damage.
They have soiled themselves, both from fear and the weapon's effect on the air spaces in their bowels.
This delayed effect enables them to either walk down the pass (or be at the forest all along) and build their den, which is partly to shelter from the cold, but also to hide from the military's return. Some of the worst injured may have hidden in the ravine, where they die.
Lyuda and Semyon collapse, breathing difficulty, and possibly resus is tried, delivering fractures, or some of these happen during the blast. Air in Lyuda's mouth and throat, she nearer the blast point, damages her tissues, a sharp intake just before, accelerating later decomposition and possibly loosening the hyoid bone.
Semyon had photographed what he can, hoping to document things, to leave evidence.
Igor, Rustem and Zina survive longest, and set off for the tent, or get flushed out the den and the military realise they will soon die, or finish them off, their breathing is noisy, deteriorating, blood oxygen levels falling, they are crawling, and then they can no longer move so freeze to death.
If Rustem was already injured in the blast, to the brain, the dizziness and vertigo which develops later leads to a fall when climbing trees, and subsequent rupture makes him pass out, creating the ice pad.
Numerous scratches, for example the underside of Igor's right arm, are caused by pine needles or tree splinters travelling at high speed, and if there was any ocular damage, from things stuck in the eyes, they may remove the eyes.
The military turn bodies the next day, explaining movement after death found at the autopsies, they realise they were hikers, indicate they knew of dead hikers in their reports, and a cover-up begins, which may or may not involve staging the tent on the ridge to draw attention away from the blast zone, which may not be at the cedar, that just becomes a survival destination, but was somewhere else in the same forest.
The area gets swept for mines, fearing some may not have detonated.