Expulsion from school and a huge damaging red mark that tarnished their untainted records - what Caroline and the others did had earned them a kind of reputation that made them look like a group of delinquents who just happened to come from a prestigious household.
In this academy, an expulsion is one of the worst punishments a student can receive - not only because it would've marred their academic records, but their family names as well. Those who were expulsed before had committed major offenses such as arson, but never the likes for bullying.
To begin with, this private institution was known to be free from this kind of outrageous activities - or at least that's how outsiders saw it. In reality, most of the students just happened to have enough power and influence to cover up this type of offenses.