From the beginning of the Casey Anthony trial, the defense had a specific story as to how Caley Anthony died. They didn't propose what if's. They didn't give several possibilities. They state their client was there and this is how it happened.
Why is that important? Because the jury was specifically told they are not to imagine. They were to consider the evidence presented in court. That means there were only two versions of events for them to consider. The prosecution's theory and the defense's statement, which we must assume came straight from the defendant.
So what was the defense's story? George Anthony, Casey's dad, wakes up and finds Caley dead in the pool; a tragic accident. He yells at Casey and says that her mom is going to be very angry. Casey is so deathly afraid of her mom's wrath (and evidently so is George) that she agrees they should put duct tape over Caley's face, put her in a bag, throw her in a swamp and pretend that nothing happened. Remember, this is the defense's (Casey's) version of what happened.
Now, just listen to the first phone call Casey made from jail when she was finally arrested. Far from being a traumatized little girl who's afraid of her mom, she holds her mom in utter contempt and has no problem expressing it directly to her. That alone totally blows up the defense's fairy tale. Remember, the jury is not to imagine alternate scenarios of their own concoction. the defense gave us a specific story in which the defendant was there. This is the only alternative to the murder scenario.
No sane person could conclude that Casey had any fear whatsoever of her mom. There is only one logical conclusion. She's lying again. The jury is not obligated, nor is it entitled to come up with new imaginary alibis for the defense.
But that's exactly what they did. Maybe they just didn't want to believe that Casey Anthony did what she obviously did. I hope it keeps them awake at night, but I suspect there's not enough brain activity between them all to enable a guilty conscience.