You are right Mark. This is by mistake, this portion of the code got changed. I have reverted this code to the older version ie. I removed the (!self.isAuthenticated) check. We are not including the addtional logic of checking if the endpoint is authenticated and then checking if the authentication is valid in the xhr method since this is the old implementation. And secondly, its tricky to implement promises within the older way of callbacks. So the fix would be part of the new implementation ie the use of request method of endpoint.