True, but the evidence in that trial -- which was an absolute clown show; I think a lot of people forget, even more than the intricacies of different evidentiary burdens, how absolutely shitheaded that prosecution team and Judge Ito were -- was pretty damning. It was as clear a case of jury nullification as one can imagine.
I watched most of it at the time and the two major culprits (other than the incompetent prosecutors) were Fuhrman and Vannatter. I pretty much called the verdict when they had Fuhrman testify about not saying nigger and then they had a huge tape of him constantly saying nigger, talking about framing niggers, and otherwise just committing obvious perjury. When your star witness gets truthnuked like that, your case is crippled.
Then Vannatter was an arrogant, supercilious piece of shit and literally admitted he'd just left blood samples out in his car for hours, often unaccompanied, just basically being spoiled, and was basically "yeah so what" when cross examined. He came across as completely unreliable.
There were also a lot of other issues. Judge Ito was retarded and let the defense, entirely improperly, call DNA evidence into question as if it were something like voodoo (the broken chain of custody thanks to Vannatter already fucked this part of the case up). Then there was the famous glove trick from Cochran. Then they let the defense basically fake up O.J.'s house with pictures of black people and stuff like that, when before they doctored it, he had basically nothing but pictures of white people on his walls.
I'm pretty sure O.J. did it, but if I were on that jury and saw ONLY what that jury saw, I would have had to acquit myself.
Nullification can happen for any reason whatsoever. The jury is never required to explain its verdict.
It actually sometimes is. On motion by a party or by the court itself, the jury can be issued a special jury questionnaire requiring it to explain its factual findings. FRCP 49 is the federal version of this.