Here is one thought:
* CA and ICA have the heated argument. ICA leaves with Caylee. At some point, that night or the next day, she dies somewhere in the car. My guess is that she fell asleep in the car seat, on her own or because of other influences, and unexpectedly died due to the temp in the car and ICA being distracted and having left Caylee to sleep in the car and not taking into account the temp and the time she was in there.
It is my observation that she has a VERY strong reaction to the topic of CA, and CA feeling as though she was a bad and neglectful mother. Actually hearing that CA is considering involving other people in taking custody away from ICA is the tipping point. ICA knows her track record is bad, and is beyond angry.
IF she returned to the car and discovered Caylee dead, everything CA said is most certainly true and she knows the hammer will drop with full force. She has just fought with her mom on this issue.
There is no way she is going to report it, there is no-one in her family to turn to. She knows that her neglect caused the death and she is responsible. She will NEVER let her mom win by knowing that she was right, after all.
She goes back to the home when she knows they will not be there and preps the body (duct tape, trash bags, etc), then disposes of her, thinking that the duct tape, etc. will surely back up the story of Caylee having been kidnapped, if they ever find the body.
I think of this because I remember when my SIL was upset at her husband and drove to my apartment to talk to me, leaving her little one in an air-conditioned suburban with the engine running and the keys in the car because he was asleep and she didn't want to wake him. I kept telling her to go out and get her son and she was so focused on what she was saying and feeling that when she did go out there, he was screaming his head off and you could not hear a thing inside the apartment (car parked right outside). I remember how angry I was at this.
Also, there have been an incredible number of "hot car" deaths. You hear about them here in Texas several times each summer. Some people just don't get it.
I was a nanny in Florida, very near Orlando, and it is so hot and muggy, even at night. People can talk outside official temps all they want to, but you have to consider that the inside of a car has no breeze, and the humidity plays a large factor in that area. And someone else posted about shoes, about there being a lack of shoes? In Florida, in that part of town and in those months, unless she was carried everywhere she went, you do not set foot outside on parking lot pavement or otherwise without shoes. The ground will burn the underside of a child's feet in seconds. Pavement is simply unbearably hot. She could have left the house that night with no shoes, but she did NOT walk out of that car barefoot the next day, believe me, unless she was carried.
I can't explain the tattoo and her acting normal for so long. It doesn't make sense at all to me.
Why did the state begin their case with the roommates? If they are moving in chronological order, why not start with the epic fight that occurred in the Anthony home?