An HTTP code still has to come back. The whizlab answer is correct.
This
link says
"Say you send a
SOAP message one-way over HTTP: the client's business logic triggers the SOAP layer to invoke the remote service. This causes an HTTP request to be sent to the server. When the request is received by the server, it should immediately return an HTTP response without servicing the request. The server-side business logic should run after the response has been returned. The response should not contain a SOAP message. An HTTP 200 or 202 status code response does not mean that the service completed successfully. A failure code, on the other hand, should guarantee that the service invocation failed. The SOAP layer on the client side blocks until it receives the response or times out."
You can also look at Mikalai Zaikin's guide regarding this.