Angular.js view not being updated after receiving message from broadcast

After saving a resource in angular.js, I want to broadcast the changes so a list view can be updated.

    function EnvironmentCtrl($rootScope,  $scope, $location, $routeParams, environmentService) {
      environmentService.get($scope, $routeParams.id);
      $scope.id = $routeParams.id

      $scope.save = function(){
         $scope.environment.$save(function(data) {
           $rootScope.$broadcast("model-update");
         });
      } 
    }

   function NavController($scope, $http, $routeParams, environmentService) {
     environmentService.list($scope);
     $scope.$on("model-update", function(){
       environmentService.list(function(data){
         $scope.environments = data;
         console.log("update called", $scope.environments); 
       });
     });
   }

The communication between these controllers when EnvironmentCtrl.save is called works ok. The console.log gets called and the data returned to the callback by the service gets correctly set in the $scope.

The relevant part of my service looks like this:

 services.factory('environmentService', [ '$resource', function($resource) {
   var environmentService = {};

   environmentService.list = function(callback) {
     var url = "/service/environment/"
     $resource(url).query(function(data) {
       callback(data);
     });
    }
    return environmentService;
  } ]);

My view looks like:

  <li data-ng-repeat="env in environments">
    <a href="#/environment/{{env.id}}">{{env.name}}</a>
  </li>

But doesn't get updated until a refresh.

This is all 'within angular' (as far as I see) and I would have thought that it would 'just work'. I've tried calling $digest from within the callback. $apply complains a digest is already in progress.

Can anyone tell me why the view does not get updated?