My theory relies on graphic details about the hikers found near the ravine. I do not intend any disrespect.
So I took a look at the scene photos and the post-mortem. Compared the positions the hikers were found in as best I could make out, to the descriptions from the autopsy reports. (It's hard for me to tell exactly what position Thibeaux-Brignolle is in in the photo, my eyes can't seem to parse the photo very well.) It looks like the injuries of Zolotaryov, Thibeaux-Brignolle, and Dubinina all correspond to where they were up against the rocks/soil of the stream. Zolotaryov's ribs on the right hand side, the side he was found laying on; Dubinina on the front of her thoracic region, which was against the ledge, and Thibeaux-Brignolle's skull, right hand side, I think that's the side that's against a smaller sort of natural ledge in the flowing water.
All this leads me to believe that three of the rav4, the aforementioned, sustained their injuries on impact with the ground (be it soil, rocks, or ice) where they were found. I.e. I don't believe anyone moved or was moved from their position after being seriously injured, but that something caused the unlucky three to forcefully collide with the ground.
I think they were thrown.
To my thinking it looks like the rav4, being the last group members alive, went and scouted around for deeper shelter in the forest (or may have scouted before the other hikers died), under the direction of Zolotaryov's military experience. He acted as if faced with an active danger, what kind I do not know, but one that would necessitate finding deeper cover. They gathered branches and ripped articles of clothing to make the seats for the den - 4 seats as at that point they were the last 4. Then, while Kolevatov was in the den, the others went back up, perhaps to gather more branches to construct a shelter, or perhaps for some other reason. Something then forcibly threw the three onto the creek. Kolevatov heard the noise, climbed out of the den, found Dubinina and Thibeaux-Brignolle unconscious, and went to comfort Zolotaryov, after which Kolevatov got hypothermia. His nose and neck could have been damaged post mortem, or could be injuries he sustained before laying down behind Zolotaryov.
Then it remains to determine what could have thrown 3 of the rav4? Something in a Siberian forest in the middle of the night that could move three adult humans through the air at near automobile speeds.
I might be missing some information. It just seems logical to me that where deep internal injuries coincide with their positions against the terrain, that they impacted more or less where they were later found. Which leads to the question of what caused so forceul an impact. (I have a couple of ideas but still want to look through the facts some more.)