Growing up, I was always 2-6 inches taller, 50-100 lbs heavier, and a lot stronger than the other kids my age.... plus I got into Jiu Jitsu at age 5.
So, this looked very familiar to me... in fact I had EXACTLY this happen when I was 13, and I did exactly the same thing to the kid, only harder (he ended up in the hospital):
No-one was ever stupid enough to try to bully me; but there were a lot of little punks who thought they would prove something by starting a fight.
They certainly proved something... just not what they were hoping to prove.
update: Youtube pulled the vid so I'm sourcing it from LiveLeak now.