Say you have the following code:

function Ctrl($scope) {
  someService.call().then(function() {
    $scope.$emit('some-event');
  });
}

The promise might be resolved after the controller and the scope has been destroyed, which will emit the event into thin air since all listeners on the scope have been removed, and the connection to the parent scope is removed when the scope is destroyed.

The $emit method should perhaps check this.$$destroyed and throw an error in case it is destroyed?