The cat and the kid both learned a lesson
The kid was crying before he hit the cat, so we can only guess what happened before, but i will assume the cat scratched him. As an owner of a cat and children , sometimes cats will scratch kids for a perceived threat that isn't real , such as petting the cat the wrong direction or simply rubbing their tummy.
Some would say the cat acted instinctively and attacked the kid for hitting him. on the flipside the kid may have acted instinctively and hit the cat for scratching him.