I may have addressed the bulk of what you're getting at in another comment; the short form of my reply is, "In the cases which 'heroic responsibility' is supposed to address, inaction rarely comes because an individual does not feel responsible, but because they don't know when the system may fail and don't know what to do when it might."

Short form reply: That seems false. Perhaps you have a different notion of precisely what heroic responsibility is supposed to address?