Retrieve response from REST API

That's correct.  I'll open a Daycare ticket.  Unfortunately for this effort, we need to use Adobe Forms (assuming it works as expected).

lesutton1,

Any further thoughts? 

You could see below the guideResultObject being returned.  It doesn't have the response in the data property.

Can you debug further and take a look at what the object is that is in your data? Sounds like instead of straight XML you're getting an object with more than one message in it.

Correct, when I add this console.log: console.log('guideResultObject.data: ' + guideResultObject.data);, the following prints in Chrome's console:

guideResultObject.data: [object Object]

Yes.  The adaptive form is invoking a Sling Servlet, which is then calling my 3rd party service.  I'm looking to surface the response of the 3rd party service in my window.guideBridge.submit success callback function.

Assuming the .data property of the guideResultObject is empty?

My REST service is returning JSON.  Here is the response I'm logging in my Sling Servlet.  I want to be able to acccess the leadId in the success callback handler.

{"status":"OK","encoding":null,"data":{"leadId":"3dc2eb71-d40a-4bdd-a16d-510636098b1d"},"apiErrorList":null}

it should contain any error messages but is your rest call taking place server side? i.e.: you're populating the response object and looking for those results in your form?