Good God,officer,why didn't you open that door??
Right. It was his biggest regret, he said later. He knew that not only did it allow irrevocable contamination of the crime scene, but he was aware that when children are reported missing and later found dead in the family home, that a family member is usually responsible.
As far as the mystery of why FW didn't see her and JR rushed right up to her (allegedly before the light was even switched on)- here's how I see it.
FW didn't know where the light switch was because it was in an odd place down low on the wall just outside the room. If he looked in a room that dark (remember- no window) he may NOT have seen her. The room was "L" shaped slightly and to see the body, you'd have to bend IN and look to the left or step into the room. Tests were done in the basement to see if there was enough light coming from the area just outside the wineceller to see inside the dark room. There was enough light that he should have seen her, especially covered with a white blanket- the wineceller wasn't THAT big. But still, unless he had his head bent INTO the room, he may not have seen her.
I don't think she was moved from another place. Only one livor pattern, and too risky once other people were in the house. BUT I do think that she may have been deeper in the room and JR went during his 2 hour disappearance where Arndt said she "thought" he went to get his mail (not true- the mail came into a slot in the front door- not a 2 hour job) and moved her body closer to the door. If you look at the pics of that room, JB's body where it was found was pretty close to the door. Even in the dark, she'd have been seen.
So to answer the last part about why JR saw her immediately- well- he knew where she was.
Think about it- JR supposedly was kidnapped from her own bedroom. When Arndt told JR to take another look around-, wouldn't you have rushed right up to her room first? Arndt said to see is anything of note was missing- a familiar doll or toy or some clothing. These things wouldn't be kept in the basement, and certainly not in the wineceller. Another suspicious thing is that the wineceller was still latched with the small wood latch (that nobody knew about unless they were familiar with that wineceller). The door could not be locked from the inside, so it's not like JB would have locked herself in there (or anyone else). The fact that JR went RIGHT to that room makes me believe he knew right where she was. And by this time, it was 1 PM- about 12 hours after her death. She already had an odor of decomposition. She NEEDED to be found. Waiting for cadaver dogs was not something that the Rs wanted to have happen.