nodeapi print faults

case 'update': 
      if ($node->moderate && user_access('access submission queue')) { 
        print theme('box', t('Post queued'), t('The post is queued for approval. 
        You can check the votes in the <a href="/%queue">submission 
        queue</a>.', array('%queue' => url('queue')))); 
      } 
      elseif ($node->moderate) { 
        print theme('box', t('Post queued'), t('The post is queued for approval. 
        The editors will decide whether it should be published.')); 
      } 
      else { 
        print theme('box', t('Post published'), t('The post is published.')); 
      } 
      break; 

The above code is listed under hook_nodeapi on drupaldocs. But when one attempts to print in a similar fashion using the update case from within a module calling the nodeapi hook, you get a "cannot modify header information..." error.

Upon closer examination, the doc is at fault. The above code proposes methods that are impossible in 4.6.3. It should be changed to drupal_set_message.