For some reason this made me think of the movie Gran Torino with Clint Eastwood. I digress.
I am only able to know one side of this story. Yours.
Instead of going to John’s door with the boys, which I imagine he found to be confrontational, you approached him in a different way. What if you first sought to understand his actions. What events or influences led him to think the boys were robbers or whatever misconception he had? You infer it was racially motivated. If so, could you be an influence to change his thought patterns?
Empathy runs both ways.
Shaming tends to cause people to dig in their heels and close their ears and mind.
Opportunity to see a better way always exists. Every minute of every day we can choose the person we want to be. Every single one of us.