If the evidence proved them innocent then we wouldn't need a jury. It is, whether you like it or not, up to the opinion of the jury. Another jury may have found them guilty or another unanimously not guilty (this I believe was a majority verdict). Like I said, you have no idea what made the jury vote the way they did but it's seems simpler for you just to claim it was all the evidence.
I don't know whether you have served on a jury but I know I have and from that I have an idea what discussions go on. Some will vote for and some against and then it's about making persuasive arguments to see if you can get an acceptable consensus. It's all about the opinion of the jury whether they think one sides argument is more convincing than the other.
The court notes will be interesting to read.
I have served on a jury and my experience is that we all thought the person was guilty of something. The police painted a picture of someone who was “up to something”. However, they could not produce a convincing argument based on the evidence they had, to demonstrate he was guilty of the crime he was accused of.
So regardless of how we felt about the accused, who was clearly a petty gangster, we had to acquit because the case against him was so weak. I suppose if you wish to call that our opinion then fair enough. Personally, we listened to the judge and took on board the instruction that if there is not enough evidence and there is reasonable doubt, we must acquit. Our opinion didn’t really enter into it.
And that’s how it works in my experience.
Edit; having said that, I do take on board your point about jury’s having an opinion and also that this was an unusual case in that they were trying to prove what they did was or wasn’t a crime rather than whether they did it or not.