What would you have liked the adults to do to solve the problem? What could they have done?
Not punish the kid hitting back at someone who was bullying him?
Not punish the kid who beat up the bully?
It actually helps to have some idea of what's going on in the school yard, ask witnesses what was going on, and IF KIDS COMPLAIN ABOUT BULLYING DON'T TELL THEM TO GET OVER IT. "You're not making an effort to fit in" is blaming the victim. I'm not making the fucking effort to fit in because the other kids treat me like dirt. Why should I bother to try fitting in?
But yes, the adults could have looked at the situation and realised that the bully was getting their just deserts. Punishing the victim who has been pushed past the end of their tether is not helping anyone.
With the above, a reasonable adult, considering evidence, has no choice but to "arrest" the kid with the chair, since the other has done no wrong other than verbal + possible pushing.
The system needs fixing by making what the bully did prior to the event actionable by the adults so it wouldn't escalate to where it did. Cameras would help.
But then what do we do with the bully? Move him to another school and let the cycle repeat?
At a school, the adults are the system, so I think my point still stands.
I've long wondered what would have fixed this... in the end the only solution I could come up with would be to segregate the consummate bullies. I'm sure smarter people could think of more adroit solutions.
We have to triage the problem. First, prevent harm from occurring to others. Second, attempt rehabilitation.
Remember that bullies also create problems in other kids which can force them to act out. Force them to drop out and get into drug use. Force them to become bullies themselves, or thieves, etc.
(hint: the shy kid probably did not suddenly decide right this moment to pop up and decide to fight for alpha status)
The teacher(s) new exactly what had happened. The administration didn't, though, and it was them that threatened to suspend me.
They did account for the circumstances; they brought in the bullies parents and all of us sat around a table to discuss it. But he squirmed out of it ("so sorry! Only a bit of fun", etc.).
The problem is; it's only when the bullied person does something extreme that the bully gets into that situation. And it didn't happen often, so this particular individual had lots of "last warnings" and final promises to be nicer.
But no one followed up and punished him properly the next time.
Teachers are there to educate, they aren't equipped properly to deal with a point of justice/behaviour.
That looks like it is a significant part of the problem: the adults most likely to exercise good judgement on these matters (teachers) don't have the power to do so.
Problem is though who has the right to decide if it was just or not. This sadly always leads to unjust sentences.
Co-worker makes racist remarks towards you: "sticks and stones" speech
Co-worker sexually harasses you: "sticks and stones" speech
Co-worker physically assaults you: "sticks and stones" speech, with added punishment if the victim defends himself
And in each case, tell the adult victim how they should be more empathetic to the bully's lot in life.