Responses
At first I thought the same too like ask some student to secretly video the bullying and put it on social media. BUT the thing is the school is allowing the bullying not just because the bully is from an influential family with money but it's because they are GIVING money to the school. The school is private and the bully's family is the one funding money to the school. The school built a whole gym on that money.
The higher ups don't want to lose their no 1 funder and since it's bullying something that is restricted among the student masses, they are willing to turn a blind eye to it as long as their pockets are heavy
I don't know why they don't just video the bully bullying the students and abusing his father's power over the school. We know how important reputation and image is in south Korea.