FormPermission.php

<?php
function beforeSave() {
  $current_role_id; // = something... role that was set to false
  foreach($data['read'] as $role_id => $value) {
    if ($value == false) {
      $record_permission_data = $this->RecordPermission->find(array(
        'conditions' => array(
          'scope' => $this->data['scope'] . '.Records'
          )
        ));
      
      foreach ($record_permission_data as $crud => $role_data) {
        $record_permission[$crud][$current_role_id] = false;
      }
      
      $this->RecordPermission->save($record_permission_data);
    }
  }
}
?>