Just started re-reading, I just realized that he did a catch and release on those psychotic teens.
They didn't actually change their tune, they just won't mess with him specifically anymore.
So essentially its like releasing unreformed criminals who are willing to murder back into society. A society with schools that rather ignore bullying if the evidence wasn't strong enough.
I guess he didn't actually do a lot of growing up in that other world. He just got OP, came back, and started jerking himself off with power.