I guess I look at this as the teacher setting the tone early to disabuse the students of any false notions of what the ethics class actually is. Shame they did it in such a shitty way, but I see that as part of their point too. I'm not sure I believe the scenario is necessarily real, but if it is, the message would be appear to be that going forward everyone must understand that this isn't going to be about how to be ethical, but how to appear to meet artificial requirements that pay lip service to ethics. A teaching to the test kind of approach.

Teaching explicitly that they should act unethically (lie about their ethical convictions) to ensure they meet future expectations of falsely signalled ethics, and teaching that through a pretty unethical act of deception and public humiliation delivers this message quite succinctly and makes it pretty clear what to expect here on in.