Why would it be extreme? Assuming that one of the family members was responsible which is arguably the most likely scenario given the evidence, there are two options especially if it was accidental. Call 911 immediately so that medical assistance can be given and admit what happened, or cover it up to protect the perpetrator. The R's chose the latter. In doing so, one would want to point LE away from the scene.
I think what many people seem to miss in trying to make sense of this crime is that the R's were not criminals, therefore lacked the criminal mindset. Faced with an unthinkable scenario, they then set about to cover up what had happened as best they could. They did a pretty good job of it too, considering that no one has ever been charged in this case, but it wasn't a perfect cover up. I imagine that there were time constraints, from the time that it was discovered there would have been the initial shock of what had occurred. Most likely followed by panic. Then to figure out what to do about it. We do not know the timeline of what happened or when it was discovered that JBR was mortally wounded or dead. But we do know that time was taken to write a practice RN and the actual note itself, which at 2 1/2 pages and while trying to disguise handwriting took some time. The body was wiped down, clothing changed, the blanket taken out of the dryer to cover her. The suitcase, certain items removed from the house, the wiping down of the flashlight and batteries, etc. There very well could have been a plan to remove the body from the house that we don't know about. They could have run out of time, or whatever plan they had may have been foiled by other occurrences. From what the evidence tells us, JBR's death probably occurred in the basement but outside of the wine cellar where urine stains were found. At some point the body was moved into the wine cellar, the light turned off and the door latched. In searching the basement, police didn't even know the wine cellar was there. If the intent was for the body to be found, they would have left her where she died and could be seen by anyone searching the basement. My opinion is that they tried to hide the body with a plan to dispose of her at some point, but realizing that was becoming impossible, they had to then do something else. Which was JR heading straight for that room & discovering the body when Det. Arndt asked him and FW to look around for anything missing or out of place.
What I do feel certain about is this.....had it been someone other than a family member, and kidnapping was the goal, the perpetrator would have actually kidnapped her, would have come prepared with whatever was necessary in order to do so, which would include a pre prepared ransom note, would not have abused her in the house, would not have left her body in the house, and would not have lovingly wrapped her in her favorite blanket. I think this also explains why JR "found" her. They could have left the house and left her body where it was, to continue to decompose until someone else found it. In my opinion, that thought was too uncomfortable for them. They had already created enough chaos and confusion for LE with the RN pointing away from the family.