Don't forget the snow, please. In itself, the injuries of the ravine 4 could be obtained by snow, collapsing on top of the hikers.
Well, or maybe a tree falling, as is plausible by the evidence Teddy provided.
And still, whatever theory you decide to follow through with, it must as well give a possible explanation for all the small injuries and mysteries. That might be one within the context of surviving the night. But if it fails to provide any, it's not feasible.