I was leaving a gas station and these two little kids were in front of the door

The one kid slapped the other kid in the face and ran away.
The kid that got slapped just looked at me with a “fml” look on his face, then opened the door for me and smiled and said “you’re welcome sir” very respectfully after I said thank you.

I don’t really know what to make of this whole encounter, a lot to take in