In my view, choosing to do nothing isn't a matter of being passive in this dilemma at all. In this hypothetical there's absolutely nothing to be done save for killing another person; Ending a human life...in apparent attempt to preserve human life.
That's in no way comparable to turning your speakers up, walking away, or failing to make a phone call.
That's in no way comparable to turning your speakers up, walking away, or failing to make a phone call.