Angularfire2 and Rxjs Observable Not firing Catch and Complete Methods

i did an auth on my site, it works fine, but i want to handle errors, for testing i caused one for this purpose with this return from firebase: "An account already exists with the same email address but different sign-in credentials. Sign in using a provider associated with this email address.". Im trying to write an RXjs observable to do that, with the following code:

private subscribleAuth() {
    this.af.auth
        .subscribe(
            auth => {
                this._auth = auth && auth.auth ? auth.auth : null;
                if (this._auth) {
                    this.loginState = 'logged';
                } else {
                    this.loginState = 'login';
                }

            },
            err => {
                console.log('error'),
                    this.loginState = 'error';
            },
            () => { console.log('done.') }
        );
}

My console never show the 'error' or 'done', so anything i put inside the err code doesn't work.

note: I know what causes that firebase return, i just want to know how treat it and why the code i wrote isn't worked as expected, when no errors are returned the site works as expected with the same observable.

I'm using angularfire2: ^2.0.0-beta.5 with Angular 2.0.0 final

EDIT 1: even the official github project tells you to get the user as an observable and subscrible to it on Override configuration / No config Example app section..

EDIT 2: reported as an issue and maybe it's really a bug, gonna keep this post updated. The workarround by now is using this code written by yashmurty on github:

import { AngularFire, AuthProviders } from 'angularfire2';
import { AuthBackend } from 'angularfire2/auth/auth_backend';

export class SocialmenuComponent {
    constructor(public af: AngularFire, private _authBackend: AuthBackend) {
        // this.af.auth.subscribe(
        this._authBackend.getRedirectResult().subscribe(
            (auth) => {
                if(auth) {
                  console.log(auth);
                } else {
                  console.log('User Not Logged In');
                }
            },
            (err) => {
                if(err) {
                  console.log('Error in auth.subscribe : ');
                  console.log(err);
                } else {
                  console.log('No Error detected in auth.subscribe');
                }
            },
            () => { console.log('done.') }
        );
    }
}