Maybe they will argue that going off on her own for 31 days gave her a sense of adulthood and freedom. Kind of how when you leave a abusive relationship you sometimes get this feeling of empowerment. I don't think it will fly, but they can try.
What I DO find weird is when CA came to Tony's house KC was scared. Per Amy, CA told KC to get her stuff and we are leaving. KC did just that. Acting like a child, got in the car as told. In my opinion, KC is scared of CA somewhat. I think CA thought she could bully KC into telling her where Caylee was and when KC would not give in, she KNEW something was wrong.
I think ICA was afraid CA was going to blurt out her dirty little secrets (no job, lying, stealing, not graduating, etc) in front of Tony. ICA fed Tony a load of BS saying she went to Valencia, had a great job as an event coordinator, had a personal nanny, thousands in her bank account, etc.
CA was demeaning toward ICA in front of Jesse saying something like I don't know why you're with her, she has no job (and a few other things I can't remember). It was bad enough that Jesse felt he had to stand up to CA and tell her not to talk about Casey in that manner.
Casey was on her very best behavior in front of Tony and his friends...cooking, cleaning, buying food/beer for the house, sex, etc. In fact, one of his friends did an interview and he said he told Tony he needed to marry her up so she must have put on quite a show.
ICA did not want CA ruining her relationship with Tony by blurting out the truth and she did to some degree. CA told Tony that he better be rich because she'll rob you blind (paraphrasing).
If CA found ICA when Tony wasn't around, I think they would have had a massive fight. Both sides dropping the 'F' bomb to each other, CA threatening to take Caylee, ICA threatening the same.
I guess what I'm trying to say in way too many words is ICA wasn't afraid of Cindy. She was afraid of what Cindy might tell Tony. Take Tony out of the picture and Casey would have been ready for a knock down drag out fight with Cindy, then steal money from her the very next day.
IMO