Yeah, I left out some of the details of the case, just because my comment was already long.

1) We heard a conversation between the senior officer and the arresting officer. (Actually a reading of a transcript of the conversation, because the original recordings were "lost".) I don't remember all of it, but the gist was the trainee asked if she should charge the defendant with a DUI and the senior office replied something like "It's your call. We could go either way."

2) The jury was never actually told the defendant's BAC. I don't know exactly why, but my impression is there was some technicality that made the test inadmissible.

3) We heard testimony from the arresting officer about the field sobriety test. However, she was a new officer still being trained, and this was only like the 5th real field sobriety test she had conducted. And the senior office had her restart it about halfway through, for reasons that we weren't allowed to hear.

4) We heard testimony that the guy had drunk ~5 beers in the 2 hours before the cops arrived.

I'm sharing those now, because they're the crux of the arguments I made.

I tentatively started out trying a line of reasoning that if the senior officer thought they could have not charged him, that means the cops have discretion about when it's appropriate to enforce a law fully. And don't we as jurors have a similar right. Isn't that our role in this? If it's just a matter of enforcing laws, a judge is better qualified. Our humanity and discretion is the point of having a jury of peers.

I tried reminding people of times when they probably broke this law, e.g., tailgating, at the beach, at a campground. There are lots of instances where somebody might have their key in the ignition, while consuming alcohol, but they shouldn't be charged with a DUI. There's the letter of a law and the spirit of the law. Yadda yadda.

I actually thought I was getting to some folks, until the foreman reread the judge's instructions to the jury, which were basically, "Your duty is to apply the law as it is given to you, whether you agree with the law or not." That type of wording is common in jury instructions, but I think it should be disallowed. It immediately shut down that whole semi-jury-nullification argument I was making. The rest of the jury felt they had to enforce the law – even though I tried to make the case that cops are also duty bound to enforce the law and they use discretion about when to charge people, likewise with district attorneys. They wouldn't buy it. The judge's instructions were too authoritative – or I wasn't a good salesman.

So, I figured I'd pushed the jury nullification envelope as far as I could safely. I changed my tactic to argue that I didn't think the guy was drunk – at least not beyond a reasonable doubt.

We didn't find out his BAC. His sobriety test was inconclusive, for me. And while 5 beers in 120 minutes is a lot, this was a pretty big guy, probably 6'1", 230 lbs. That's my general weight class, and I've used the BAC calculators before and played with a friend's breathalyzer. I know I can have 3 (12oz, regular bav) beers per hour and stay right around 0.08%. (I wouldn't drive after drinking 3 beers in an hour, but it's good to be aware.)

So I just kept arguing that I wasn't convinced that he was drunk. One of the other jurors actually got pretty belligerent, a few exchanges like this (almost verbatim):
Them: "COME ON! You really don't think he was intoxicated after chugging 5 beers? Is that how you party? Drink a sixer and hop in the car?"
Me (ignoring the ad hominem bullshit): "He probably was intoxicated. But likely is not the same thing as 'beyond a reasonable doubt'. And I'm not giving this guy a DUI for possibly, maybe being intoxicated and playing music from his truck!"

He kept pushing me, and finally I just turned to him and said, "Look, I don't have to convince you. I don't have to even talk to you. I'm voting my conscience. You vote yours." That finally shut him up, mostly. In his defense, this was like hour 7 of deliberations.

I'm really glad I had this experience, but it was somewhat frightening to watch what the other jurors would do just because the judge gave them instructions. :(