I hope this is stressed to the jury. *
When Casey was being interviewed by the police officer, he repeated to her that accidents happen, and if this was the case, now was the time to state it, but she did not budge....
I believe this was because what happened was so bad, that NOTHING was worse than the truth. So she had nothing to lose to lie, even poorly; dragging officers to her fake place of employment. It was all done to stall and buy time; focus the search on a fictitious nanny so her daughter's body would have enough time to decompose and destroy the evidence. If Caylee had really drowned, Casey would need her remains to be found to show the evidence of drowning. She knew that what she did was worse than anyone could even conceive and so it made perfect sense to lie and lie, to stall her being found, and so hide the truth forever.