1. The portable oven they had, was not used this fateful night. This means it is proven impossible that the stove could create an accident.
Is it possible for the stove to have been disassembled after use, and the wood to have been reduced to embers, with the exception of one piece they didn't use? The smoke would have been the result of a draft from opening the tent when one of them went out to take a leak and then returned, causing the embers to be fanned into smoking, and blowing out their candles. The darkened tent quickly fills with smoke. Zina and at least one other has a nosebleed as a result, leading them to cut the tent in an attempt to vent, and then exit when that fails.
2. Even if the oven had been used, it would be highly unlikely because people who leave a tent because a stove accident do not flee long distances.
Unless they couldn't vent the tent in a timely fashion, leading to concern about being exposed to the wind poorly dressed, and decided to build a fire and look for shelter elsewhere for the night.
1. How likely is it that people who leave a tent because of smoke formation and ventilation difficulties decide to go far from the tent, and does it seem probable that any adult person could believe that such action would increase their chances of survival in winter conditions? There simply is no ground for assuming that there was any smoke in the tent that could force the nine to leave their tent. There is still less reason to believe that people who had smoke in their tent would choose to move more than a kilometer away in the cold, instead of working to remedy the situation in the tent. If there had been smoke, nothing would have prevented the trekkers from staying to solve the problem right there.
2. Zinaida bled from the nose during the last night of her life, she evidently had blood in her face when her body was found.
But Zina had much more serious trouble than just a nosebleed, as is clear from the autopsy report:
"dark red abrasion on the right frontal eminence"
"dark red abrasion on the upper eyelids"
"brown red graze on the bridge and tip of the nose"
"numerous abrasions on the left cheekbone"
"bruised skin on the right side of the face"
"brown-red abrasion on the back of both hands in the area of metacarpal phalangeal and inter-phalangeal joints"
"wound with jagged edges and missing skin on the back of the right hand at the base of the third finger"
"a long bright red bruise 29x6 cm in the lumbar region on the right side of the torso. The bruise looks like left from a baton"
These injuries were of course not caused by smoke, and frankly speaking it is extremely unlikely that they could have been the result of her stumbling around in the snow either.