Parent methods (regardless of visibility) are also available to a ReflectionObject.  E.g.,

<?php
class ParentObject {
  public function parentPublic(  ) {
  }

  private function parentPrivate(  ) {
  }
}

class ChildObject extends ParentObject {
}

$Instance = new ChildObject();
$Reflector = new ReflectionObject($Instance);

var_dump($Reflector->hasMethod('parentPublic'));  // true
var_dump($Reflector->hasMethod('parentPrivate')); // true
?>