Another juror interviewed by the television station NBC10 in Boston, the jury’s forewoman Roni Carlson, said that because the judge’s instructions clearly stated that if jurors had considered all the evidence but still had reasonable doubt about the charges against Clancy, the killer mother, they had to acquit her. Since the lone hold-out admitted that he had reasonable doubt that Clancy was guilty (meaning that she was “not guilty by reason of insanity”) Carlson said that she excitedly started to fill out the three verdict forms, got as far as writing her signature on each sheet, but then heard the Lone Juror say, “I’m still not going to say that she’s not guilty by reason of insanity.”

This isn’t hard. The so-far unidentified juror playing the part of Henry Fonda, the initial hold-out in “Twelve Angry Men,” was engaging in jury nullification, which was his right. It is a right every jurisdiction acknowledges, and is a bulwark of our democracy. Another term for the act is “the juror’s veto.” Technically, jury nullification is when a jury returns a not guilty verdict even though jurors do believe beyond a reasonable doubt that the defendant has broken the law; this one is unusual, because the juror veto is being used to insist on a guilty verdict as a principled stand against a law that he apparently believes unjustly allows a defendant to avoid accountability and punishment for the most heinous of crimes.

I know quite a bit about the lone juror phenomenon, because I studied it carefully in the course of directing Reginald Rose’s screenplay for “Twelve Angry Men” on stage four times. (Self Promotion Dept.: I’m even given credit for helping to get the stage version on Broadway in “Reginald Rose and the Journey of 12 Angry Men,” by Phil Rosenzweig, Fordham University Press; 314 pages; $27.95). What casual viewers of the film often miss (and what the first adapter of the screenplay for the stage never grasped), is that Juror 8 (Fonda), probably frees a murderer…just not one who was proven guilty “beyond a reasonable doubt.”

The Clancy trial’s holdout juror seems to believe that there are some crimes so terrible that society must punish them for its own preservation, and that the insanity defense shouldn’t save them. This is similar to the justification of the Nuremberg Trials: even though following lawful orders usually will insulate a subordinate from accountability in wartime, the world made an exception in the case of Hitler’s genocide. The war crime tribunal stood for the principle that some crimes could not be tolerated in a civilized society, even during wartime.

The juror may also have been repulsed, and justly so, by some of the female jurors who may have approached the case from the same disturbing perspective as those women in pink cheering for a triple child-killer outside the courthouse. If I had been in his place, and one of the jurors said to me, “Why are you so bothered by the fact that this mother viciously murdered her three children?” I might well have replied, “It’s the fact that you women are so eager to rationalize a mother killing her three children that bothers me. In this case, I believe that the state’s laws involving the insanity plea are wrong and will result in a terrible injustice for those murdered children. So I’m voting to convict.”

There is another parallel with the Reginald Rose classic revealed in the juror interviews. The third juror interviewed, Paula Devlin, said that the holdout “completely disregarded” what the nurses on the jury contributed to help interpret medical reports from the hospital where Clancy stayed after she killed her children. That alone justifies a mistrial: jurors are not allowed to offer their own evidence or expert testimony in the jury room. In “Twelve Angry Men,” Juror 8 produces a switchblade he bought that looks exactly like the murder weapon, which had been described in the trial as “unusual.” It’s a dramatic moment in the movie, but also juror misconduct. So was the nurses using their alleged expertise to frame evidence in the Clancy trial.

Jury nullification can be unethical, of course: deranged African-American lawyer Elie Mystal has advocated that all black jurors refuse to find any black defendant guilty regardless of the charge on the grounds that the justice system is racist. Nonetheless, jury nullification is an essential safety valve in our justice system and the epitome of the core American principle that one individual can make a difference if that individual has the courage and fortitude to take a stand. The Clancy trial’s hold-out juror took a stand that mothers shouldn’t kill their children, and if they do, whatever the reason, a civilized society should punish them harshly. In ethical terms, it is moral absolutism.

He deserves our respect even if we disagree.