Others may chime in but in finding of facts the trial court is considered locked in. Appeals are usually won on procedural, legal angles and other issues. It it rare that an appeal will set aside the fact finding of the trial court as I remember.
From the little I've read of this case (just this thread), it's possible there was no "error of law," and even if there was, the standard for overturning a lower court is "tougher" than the standard used by the lower court.
See Reversing a Conviction - FindLaw for a little bit more.
Tough as it is to get, this remedy is easier to get from a trial court than from an appellate court.
The remedy of jury reversal only goes one way, no judge can reverse a not guilty verdict.
Not true. All trial judges have that authority. Been around from the get go. It is just VERY rare.
How are judicial set-asides illegal?
Seriousness of the charge vs. facts?
Having served on a couple juries, I can attest that the jurors are not always rational and many are run by their emotions instead of their brains. The same jury that might let an obviously guilty perp, who assaulted and almost killed a man, go; might also be prone to wrongly convict a man charged with raping a young girl.
I've also seen what happens when a judge and prosecutor work together to railroad someone - having a judge willing to do this, especially with the judge's reputation, tells me that the jury got it really wrong.
That, and the fact that our justice system is based on the premise that it's better to let 100 guilty folks go than it is to falsely convict one innocent should mean something once folks clear the air of emotions.