If he had practiced a form of combat he'd be able to deal with the little **** without breaking sweat. Training in martial arts teaches discipline and control and that fighting is a last resort usually to be used in a time of great danger, not some kid winding you up to get his ratings on youtube.
Do you remember that Bruce Lee film where he power bombs someone? Nah, me neither.
So maybe the kid has practiced a form of combat but takes into his own hands when to use it?
To sum up, the kid was bullying him, he punished the little **** with a nice - deserved - powerbomb (which didn't break his neck and paralyze him). It's all good.