Fatal error: Cannot unset string offsets

sites/all/modules/filefield/filefield_widget.inc on line 483
Issue is this http://stackoverflow.com/questions/8610636/is-this-a-php-bug

This works

  if (isset($item['data']) && is_array($item['data']) && isset($item['data']['description'])) {
    unset($item['data']['description']);
  }

This does not

  if (isset($item['data']['description'])) {
    unset($item['data']['description']);
  }