I would probably not go directly to a government agency, but I would not hesitate to file some sort of complaint. That my 'superiors' would attempt to prohibit me from making a complaint I would see as an unnecessary restriction from my own rights as an individual, rather than a mere employee, or a reciprocal 'inferior.'
To the person below me: if a person physically or mentally abused you, but did not seriously or critically harm you, yet if the offender seemed obviously not 'in their right mind,' would you still take lawful action?
