Could this have been a "mercy killing"? Example, someone (I wont say who) bashed her on the head, parents found out, maybe they knew she was dying or thought she was dead, maybe she was having crazy breathing (sorry, I dont know how to put that) and maybe they did it thinking they were helping her, if they knew she would have died, they couldnt take her to the ER, so they set this plan in motion. DeeDee, the pineapple just sums it up for me as well... cannot believe they denied owning the bowl, did they honestly think people would believe an intruder would bring that in with him(well IDI would), but owning up to saying yes, she had pineapple when we got home would mess up their story about her being asleep. Maybe they did not know she ate the pineapple, she could have helped herself, or had help from someone else. But the pineapple puts her being awake after arriving home. Say they were innocent, when they woke and thought she really was kidnapped, would they have noticed the pineapple out on the table while searching for her, If so they would have brought it to attention, I would hope(example: there is a bowl of pineapple out on the table, we did not leave that there, it wasnt there after we got home from the party, etc) But instead they try to deny even owning the bowl.
I don't know that I would call if a mercy killing, but if Burke did hit her, it is quite possible, IMO, that the parents thought she was beyond help and acted to protect their other child.
I have told this story before, but perhaps it bears repeating. Last year I witnessed a teenage girl hit in the head by a flying object (shot put, I believe is the term). She immediately went into convulsions and I thought for sure she was dying. She then lost consciousness. Again, I thought she was dying.
She stayed overnight in the hospital for observation and was home the next day feeling fine and with no memory of the incident.
Since the head blow to JonBenet was determined to be much more severe, in that it would have caused death, I have no trouble imagining that the parents may have thought she was beyond hope.