The cover of Yussel's Prayer: a Yom Kippur story spells out that Barbara Cohen is not the author, but a reteller of this story. I discovered this after I read the (Sydney Taylor award winning) book that felt familiar. It reminded me of the Baal Shem Tov story, where a simple, but honest Jew did not know the words of the prayer, but because of his pure heart reciting the alphabet was sufficient to be heard by G-d. Here we have a simple, but honest lad, who is not allowed to go to the shul for Yom Kippur and is asked to tend the cows instead. Meanwhile the whole village is praying and towards the end of the day they are waiting for the rabbi to start the closing prayer, n'ilah. The rabbi waits till he hears the simple melody from the boy's flute, because that is the only prayer he heard all day, that helped to open the gates of heaven (so it could be closed again.
I am a bit confused about the lesson of the story. It is obviously intended to emphasize the importance of kavvanah, devotion and attention when praying. I say obviously because it describes in details what all the other people at shul were thinking of instead of paying attention to the words of the prayers. The reason I am confused is that I am used to the idea in children's books that both the good guys and the not-so-good guys get what they deserve. Here the boy's price is that he is invited for dinner, which is fine compared to his social status. But all those people who did not have their hearts set on their prayers just walk away freely. Even the one who learns the importance of the lesson, Reb Meir, was not reprimanded.
My confusion shows my personal limitations. I am aware of the pedagogical advantages of using only positive reinforcement. I also saw that in Hasidic communities this is practiced. As the book describes such a congregation it follows the same idea: focusing on the positive and neglecting to punish negative behavior explicitly in the hope that the positive examples will teach the culprits. Now, that I worked it out, I am less confused. Thank you for listening/reading.

A cowherd's simple bu sincere Yom Kippur prayer is instrumental in ending the day's fast. ( )

A cowherd's simple but sincere Yom Kippur prayer is instrumetnal in ending the day's fast (from the summary).