This code is not necessarily wrong as is. What you want to be careful about is javascript outside of the angular context (jQuery callbacks/plugins etc) manipulating $scope values because those functions will not trigger an angular digest loop, and will result in a disconnect between the DOM and the $scope.
Here is some more information about this cycle and what you need to know about it: http://jimhoskins.com/2012/12/17/angularjs-and-apply.html
Here is a common use case with jQuery (and also why you should try to use angular services (ie: $http) instead:
// When you manipulate the $scope with a non-angular callback,
// you have to run $scope.$apply() to tell angular about the
// change in order to repaint the DOM
$.get( "/getUser", function( data ) {
$scope.user = data; // set $scope data in callback
$scope.$apply(); // run digest so anything in the DOM binded to the {{user}} model gets updated
});