Jurors are allowed to ignore the judge's rules. Our first chief justice of the USSC even said so. That IMHO is the main point of having juries, to be triers of the law as well as the facts in exceptional cases. But they need to go down that road carefully and not often.
The last time I was called for jury duty, unlike previous times,
voir dire was conducted as a group rather than individually. We were under oath so, when we were asked if anyone might have trouble following a judge's instructions, I had to raise my hand. Much hilarity ensued.
First, they immediately sent all the other prospective jurors out of the room. Then BOTH attorneys ganged up on me and told me that jurors have to follow the judge's instructions. I told them I disagreed. Finally, they sequestered me in a small room while they found a judge, who then proceeded to tell me the same thing. I told her, as respectfully as I could, that I disagreed and that John Jay (the first Chief Justice) had disagreed. The judge told me that my understanding was incorrect. She dismissed me and told me to go home and do my homework.
So I did. I looked up the case (
Brailsford v Georgia) and wrote the judge a letter to inform her that I had done as she instructed, found the case, and that I still believed I was correct. The judge never responded -- and I haven't been called for jury duty since. I think I'm black-listed.