I wasn't aware that there was any moral courage displayed in the story. The main character, Dave, is at heart a petulant and cowardly boy that shows no moral courage whatsoever. Take for example his reaction after he shot Jenny. The morally courageous thing to do there would be to go to his parents, confess about the gun, return the gun, then go to Mr. Hawkins and tell him what he had done and then offer to pay for the mule. Most importantly, he would have followed through on the promise to pay for the mule, instead of skipping town. Instead of doing the above, which was the morally courageous thing to do, he lies about how Jenny died, lies about his intentions to work of the debt to the mule, lies about returning the gun, then goes and angrily points the gun at Mr. Hawkin's house, wishing he could shoot one more shot. Then he bails, skipping town on a train.
The moral courage absent in Dave is the courage to own up to one's mistakes and then to be willing to pay for them. If Dave had done that, if he had lived up to that moral courage, then he might just have made the distinction of manhood, adulthood, respect and power that he sought for so angrily in the story. But instead, he cowers and lives up to the title of being "almost a man".