Apparently it wasn't. This is the prosecution's fault for not putting together an adequate case. They decided to go through with circumstance. They had 3 years and yet still couldn't piece together proof of how she actually died. That ought to tell you something, like maybe everyone is wrong. That is called reasonable doubt. And that is all it takes. In this country you're innocent until proven guilty. Not the other way around. Like the verdict or not, the system worked as intended.
This is why we have the system we do. None of us were in the courtroom so we don't know. If you left it to the mob mentality in this country she'd have been stoned to death. I'll take our system as is.