BBM --
This does fit in perfectly with something that's always bothered me. According to AH, when she took CA to kc, CA immediately told kc to get her things and leave with her. It doesn't seem she asked about Caylee's whereabouts at that time nor did she question if Caylee was at TL's. Since there would be a good chance Caylee would be with kc (in CA's mind), why would she assume/know she wasn't there?
Also, in line with that theory, CA spouting off to AH in the car about all kc's wrongdoings certainly seems unlike her, as she is all about her family appearing "perfect". Could this have been CA laying the ground work? Maybe at this point, she had no idea what kc has said or done, so she needs to start getting the word out about what a liar she is . . .