Thank you to Blink for starting the new thread!
Even with all of these layers being discussed and picked apart I think we still have a story that can be resolved with Casey speaking the truth. I doubt there was a call from Caylee, but that is because there is a pattern here of Casey going to extreme effort to support any story she happens to be telling at the moment.
Let's remember that it was Casey's DAD that took LE aside once they had interviewed Casey and said privately that he did not believe she was telling the truth. I think Casey's parents are, in a way, participating in the charade with the hopes that if they appear to still believe Casey, Casey will eventually produce Caylee. JMO.