function order_confirmationAction($order,$token) { 
        $client = new \GuzzleHttp\Client();
        $answer  = $client->post("http://www.fullcommerce.com/rest/public/Qtyresponse",
                    array('body' => $order)
        );
        $answer  = json_decode($answer); 
        if ($answer->status=="ACK") {
            return $this->render('AcmeDapiBundle:Orders:ack.html.twig', array(
            'message'   => $answer->message,
        ));
        } else throw new \Symfony\Component\HttpKernel\Exception\HttpException(500, $answer->message);
}
If $client->post() response status code is an "Error 500" Symfony stops the script execution and throw new exception before the json decoding. How can I force Symfony to ignore $client->post() bad response and execute till the last if statement?