Holy crap... nanny state?

I'm not agreeing in any way with the manager in this situation; public humiliation of employees by managers is both morally cowardly (bullying someone from a position of power) and ineffective over the long run (in my opinion). But still, stress happens in most jobs. Often times it is caused by a combination of home and work factors. It's ridiculous to make "preventing stress" a legal duty of employers, because that's not wholly within an employers control. Example: Faulty machine used to serve customers blows up at work at now you have a lot of angry customers. Stress ensues.