liveuser_admin _getUsersByPerm

Hi, I'm wondering why this method throws an exception when no users are found? It's just normal behaviour that when I specify a set of filters I may not get any results. It's like PEAR::DB would raise an exception if I did something like $db->getOne('SELECT email FROM table WHERE email='somecrazyemailthatdontexisst@example.com'); Or am I misinterpreting things here? I pasted the relevant code below. Jeroen LiverUser/Admin.php

    function _getUsersByPerm($permFilter = array(), $first = false)
    {
        if (!is_object($this->perm)) {
            $this->_stack->push(LIVEUSER_ADMIN_ERROR, 'exception',
                array('msg' => 'Perm container not set.'));
            return false;
        }

        $permFilter = array('filters' => $permFilter);
        $permFilter['select'] = $first ? 'row' : 'all';
        $permUsers = $this->perm->getUsers($permFilter);
        if (!$permUsers) {
            $this->_stack->push(LIVEUSER_ADMIN_ERROR, 'exception',
                array('msg' => 'Could not find user in the permission backend'));
            return false;
        }