Imo, its good that they're pursuing this since there's clear evidence of what the adults did, while arejola and company still needs to prove what they allege in court. And even if the zobel party countersue, if the arandia assailants are minors, they wont be criminally liable while the other hand arejola and the other company are. From the looks of it this is prolly the reason why the zobel party hasnt released a statement yet. Either they need things to cool down or they're still gathering evidences for their defence.
As for the Rich always wins adage, it may actually bite em back. While public opinion is never admissible in court, no judge will attempt to screw this up due to the backlash they might face from it, heck no politician will touch this, even ones from la salle since itll negatively affect em in the next election. It helps that arandia is channeling david v goliath vibes and them pursuing this could bring positive spotlight to the school. They might believe that a school defending their own may lead to increased enrollees.