Prefer if else to if not else. Also, it's a nice practice to keep the conditional code paths short so you might do something like

    var component = { eventId: result.id, ical: ical };
    if (event.isRecurring()) {
      component.isRecurring = false;
    } else {
      component.iterator = iter;
      component.lastRecurrenceId = lastRecurrenceId;
    }

    stream.emit('component', component);