It goes without saying that mechanisms in the back-end need to be implemented in order for AUI to provide a great user experience.
For instance: - On error, an action should be retried. - Long-lived processes should be queued and upon failure, requeued.
Hopefully, the user won't reload the whole javascript app before this action is successfully completed and should never notice it failed in the first place.
It's not perfect, but I find that it is better. There's definitely work to be done on the error handling front. The UI should be able to clearly notify the user when something he previously did, didn't work.