Has the full autopsy report been produced or released? From what I'd understood, it hadn't but only two things had been leaked- the COD being asphyxiation and the bite marks. Which don't say much, or explain anything without the context of other injuries. Someone could have heard 'asphyxiation' and tuned out the rest while writing the report.
If the kids got choked by an adult, there would massive, massive injuries to their necks- internal or external. If they were poisoned by carbon monoxide, there would be skin discoloration. Chest compressions, I'd imagine a lot of trauma to the chest and neck. There'd be popped vessels... there are lots of indicators for different things. Just going 'asphyxiation, must be the adult!' isn't enough. There's not enough that's been released one way or another that proves beyond a shadow of a doubt, 'whodunnit'. People were asking how the snake could have done it without waking the kids, so I brought up a scenario where it could have asphyxiated them without constricting.