Work log is shown on all pages

I think the problem is in casetracker_work_nodeapi:
1/ no check of access rights
2/ no check of content type

Solution for 1

function casetracker_work_nodeapi(&$node, $op, $a3 = null, $a4 = null) {
  if (user_access('log work') || user_access('manage work and rates')) {
    switch ($op) {
      case 'view':
        $display = views_build_view('embed', views_get_view('casetracker_work_node'), array($node->nid));
        $display .= drupal_get_form('casetracker_work_entry_form', $op, $node->nid);      
        $node->content['casetracker_work'] = array(
          '#value' => theme('fieldset', array('#title' => 'Work log', '#value' => $display, '#collapsed' => true, '#collapsible' => true,)),
          '#weight' => 10,
        );
        break;
    }
  }
}