False positive for UnusedPrivateMethod when called statically

This code will cause a UnusedPrivateMethod warning:

/**
 * Coder test.
 */
class Test {

  /**
   * Public.
   */
  public function publicMethod() {
    return self::privateMethod();
  }

  /**
   * Private.
   */
  private function privateMethod() {
    return TRUE;
  }

}

If privateMethod() is marked static, the problem goes away. A person cleaning up their code might just remove the apparently-used method and thereby break their code.