O.J. Simpson was found not guilty of murdering his wife. But is there a possibility the jury got it wrong?

It may be that the jury believed he was guilty but decided that the evidence wasn't strong enough for conviction. For a jury, "getting it right" means accurately assessing the strength of the evidence.

I know essentially nothing about this particular case.

Nah, no way.

I mean he wrote a book afterwards describing in vigorous detail how he would kill his wife if he were to do it. Which is something a perfectly innocent person would do, right. Right...?