Username ambiguous

When a user who is logged in with CAS, is given enough rights to edit information of other users, there goes something wrong.
This comes to outing when trying to retrieve an e-mail address, based on the username ($user->name).
This username is the username of the 'logged in' user, but this is not necessarily the username of the user you're editing.

In the following fragment, $user->name should be replaced by $form['_account']['#value']->init.

          if ($ldap_config_name = _get_ldap_config_name($user->name))
          { 
            _ldapauth_init($ldap_config_name);
            $ldap->connect();
            $cas_ldap_email_attribute = (string)variable_get('cas_ldap_email_attribute','mail');
            $ldap_entries = $ldap->search($ldap->getOption('basedn'), $ldap->getOption('user_attr').'='.$user->name, array($cas_ldap_email_attribute));