It's really the way that a person who's a witness frames the incident that they witnessed if they think it has an ethical dimension to it. That's a dimension where it's labelled as wrong in a moral sense rather than just wrong because there's a policy against it. If they have a belief that the behaviour is harmful, that it's not a proper behaviour, or that it's a behaviour that causes harm to the other person, that is usually how they define it when talking about ethics. If the person sees harm coming from the behaviour, then it's classified as unethical behaviour.
On May 28th, 2013. See this statement in context.