A short review this,
I have to admit that I kind of missread the synopsis of the story.
"A lawyer is surprised and pleased to find himself sitting on a jury trying a man for attempted murder of his wife's lover."
I actually thought that the narrator of the story was the one who's wife had been cheating... you can imagine my confusion (it's actually quite early and I have not had my coffee, so I have an excuse.)
The story itself is really nicely handled and gives the reader a little insight into the workings of a jury's thoughts during a trial. The narrator is, himself a lawyer. I get the impression that he has only recently passed the bar exam. He's on jury duty and is taking the opportunity to gain some idea of how the jury members see the prosecution and defence's arguments.
Essentially, this little vignette is a discussion of how our narrator comes to make promises as to how he will behave in court in the future.