No, the liberal BS is from you. It is liberal BS that says supervisors are legally liable for verbal abuse — physical abuse, yes, verbal no. And yes actions have consequences. The kid could have gone to his supervisors supervisor, he could have quit etc. And, the supervisor could have been fired if warranted. But it is complete liberal BS to say legal liability for verbal abuse.
You’re arguing against existing law. Don’t like it? Work to get it changed. As it stands, supervisors most definitely are legally accountable for verbal abuse and you know it.