Refresh isn't working with data provided by service unless it's explicitely copied

Example (non-functional) at: http://plnkr.co/edit/5171yuyhlQ7eHEjOSitu

If I click "Refresh list", list just stucks at "Loading..." phase, even getData() gets executed.

Workaround is to copy "data" ($scope.grid.data =data; -> $scope.grid.data = angular.copy(data);), but that seems a bit stupid way especially if there's bigger data lists used.
