If Jesse recants actually hearing Caylee's voice then it goes back to Cindy being the last person physically to have Caylee with proof on July 15th at the assisted nursing center. There has been no other sighting or proof after that video was taken. No one has stepped forward from anywhere to say they saw Caylee after that point in time.
I have said this before, but someone should have seen her like: a Mcdonalds' employee, someone at the grocery store, a random person seeing them at a park playing, or even someone seeing Casey drive down the street with Caylee in the car. No one saw her, talked to her, or had contact with her after she was last known to have been with Cindy...not Casey.