MVC4 with latest available OAuth libraries

Repro

1. Register UserA
2. Register UserB
3. Logged in as UserB add a Google Login
4. Log Off UserB
5. Login as User A
6. Logged in as UserA attempt to add same Google credentials as used in UserB
   

Result
When adding external credentials to a user account when those external credentials already exist in the membership repository for another user will automatically log the current user off and on as the other user.

Expected
I would expect an error stating the external credentials could not be associated with the current account because they exist for another account.

        {
            var userName = OAuthWebSecurity.GetUserName(result.Provider, result.ProviderUserId);

            if( !String.IsNullOrEmpty(userName) && 
                String.Compare(userName, User.Identity.Name, true, CultureInfo.InvariantCulture) != 0)
            {
                return RedirectToAction(MVC.Account.ExternalLoginFailure());
            }
        }