Has to be 12 guilty, 0 not guilty. Even if 11 of them think guitly and 1 not guilty, the verdict will be not guilty
This is completely wrong btw.
If the jury don't come to a unanimous verdict, the judge will often revise it down later to a majority one (majority being 10-2). If they can't come to a majority, then the jury is declared hung and the trial is over. Prosecution will usually seek a retrial unless there's a good reason not to. Hung juries are pretty rare though.
Why would the judge say "The only score is 12-0" if that's not what he meant? Surely I wasnt 'completely' wrong..? If it's not 12-0 at this point, it's not guilty. What happens after that comes next
A hung jury is not "not guilty".
Assuming the judge does stick with his direction of unanimous, the only NG verdict is if all 12 jurors decide he is NG.