OK after checking into it more closely the default moderation stuff is fine, yes. When you click "hide" there is no option to reshow it.
However, any post that is caught by a filter plugin allows the behaviour I described above. For example a basic filter like this lets the user bypass moderation:
public function filter_answer( &$answer, &$errors, $question, $oldanswer )
$userpoints = qa_get_logged_in_points();
if ( $userpoints < 25 )
$answer['queued'] = true;