But that would mean using common sense and apparently they were supposed to leave that at the door....
Yes, jurors should use common sense to evaluate the evidence BUT it still has to rise to the level of reasonable doubt. Common sense tells me that Casey was involved with her daughter's death, but I can see how the jurors could have a reasonable doubt about it.
A PP mention mentioned the preponderance of the evidence. That's the standard in a civil trial, not a criminal one. Beyond a reasonable doubt sounds even worse in the FL wording - beyond any and all reasonable doubts sounds so close to beyond all doubt as to be indistinguishable.