You may be right about the lack of cover-up intent or whatever. I just don't want to exclude the possibility out of hand. Yes, looking at the autopsy photos was a bit shocking; I quickly ruled Burke out on lack of strength alone. An adult did this.
Some things to note:
researchers on forumsforjustice have noted that there were no scrapes on the body characteristic of a struggle, there was no neck muscle bruising (though the skin was bruised) which indicates struggle, and the saliva discharge was drool, also not indicative of struggle. If that's right then at minimum I think she was unconscious when the ligature was applied.
An interesting footnote is that the drool ran down the face outside the region of tape adhesive, meaning it happened before the mouth was taped. In other words, she was unconscious when the tape was applied. To me, that alone indicates a deceptive act.
I've struggled with how a family member could stomach 'faking' something like that at such a traumatic time. But that assumes they are like me...
This is an interesting fact, and one I wasn't aware of until now. Yes, I agree with you that it tilts back toward the direction of a cover up.
BTW, my gut instinct has always been that someone either in the family or close to the family killed that child. Unless the Boulder authorities come up with truly damning evidence against Karr, I'll have trouble believing he's the killer.