This was more to say "we're serious, and watch what happens if you are not as serious about it as we are"
It also screams "I'm a liability. If you don't do what I want I will hurt you, even if you've done nothing wrong." This applies to this situation but also in future situations.
charges against the employer for having such a person in their employ
That line is quite concerning. It literally means that perceived emotional harm isn't just the fault of the perpetrator but a liability on the employer. It's impossible to control other's actions and more importantly how those around them perceive them, so the only meaningful defense is to eliminate potential victims.
I have hardly ever known a mathematician who was capable of reasoning. -- Plato