I don't think anyone said they have a "sole responsibility". I was just trying to keep the discussion focused on people and not abstract entities like "managem

I don't think anyone said they have a "sole responsibility". I was just trying to keep the discussion focused on people and not abstract entities like "management" or "the business". I don't really understand your architectural example though. The presence or absence of regulations doesn't change the fact that an architect should follow an ethical course of action and design a safe building. Regulations or standards may help to be more successful at that goal but they don't add or remove the responsibility.