How to retrieve the headers from a SoapFault - php

Question

I'm using PHP's SoapClient to connect to a webservice (which is out of my control). One of the SoapFaults I'm receiving is as follows (formatted for readability):
<?xml version="1.0" encoding="UTF-8"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Header>
<Infolog xmlns="Infolog" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<InfologMessage xmlns="http://schemas.datacontract.org/2004/07/Microsoft.Dynamics.AX.Framework.Services">
<InfologMessageType>Error</InfologMessageType>
<Message>Customer 6729 not found.</Message>
</InfologMessage>
</Infolog>
</s:Header>
<s:Body>
<s:Fault>
<faultcode>s:Client</faultcode>
<faultstring xml:lang="en-US">Request Failed. See the Exception Log for details.</faultstring>
<detail xmlns:s="http://www.w3.org/2003/05/soap-envelope">
<AifFault xmlns="http://schemas.microsoft.com/dynamics/2008/01/documents/Fault" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<CustomDetailXml i:nil="true" />
<FaultMessageListArray i:nil="true" />
<InfologMessageList xmlns:b="http://schemas.datacontract.org/2004/07/Microsoft.Dynamics.AX.Framework.Services" i:nil="true" />
<StackTrace i:nil="true" />
<XppExceptionType>3</XppExceptionType>
</AifFault>
</detail>
</s:Fault>
</s:Body>
</s:Envelope>
When PHP throws the SoapFault exception, the message is the Request Failed. See the Exception Log for details. as would be expected. But what I really need is the Infolog entry from the Header. Is there any way to retrieve the Header params, other than calling __getLastResponse() and parsing the entire XML myself, which seems very clunky?
I am open to switching client libraries if that will do it - I've so far tried with the native PHP SoapClient and Zend\Soap\Client