Fatal error when enabled at the same time as the Theme Developer module

PHP Fatal error: Function name must be a string in /data/webroot/sites/domino/www/profiles/domino_profile/modules/contrib/menu_minipanels/menu_minipanels.module on line 310

The problem here is that Theme Developer (http://drupal.org/project/devel_themer) has its own hook_theme_registry_alter() that moves ['link']['function'] to ['link']['original']['function'].

I'm not too familiar with how this part of the hook system works. I've worked around by changing
return $registry['link']['old function']($link);
to

  if (isset($registry['link']['old function'])) {
    return $registry['link']['old function']($link);
  }
  elseif (isset($registry['link']['original']['old function'])) {
    return $registry['link']['original']['old function']($link);
  }
  else {
    return $link;
  }

but this feels a bit of a hack as it's adding a special case for the Theme Developer module (and an else for a nicer fallback if there are any other modules with the same conflict). Is there a better way to handle this?