Safari 6: View Source, save as HTML, AppleScript all retrieve original HTML only. Inspect Element shows post-AJAXed HTML. How to retrieve?

Same problem with Chrome: save as HTML and view source both force a reload of original document. Is this a WebKit thing?

And the same problem in Firefox. What am I missing here? Feels like something obvious.

And the answer seems to be encapsulated JavaScript: set theSource to do JavaScript “document.documentElement.innerHTML”