[whatwg] Question on "the element's Document"

[Boris Zbarsky]

Section 2.6, item 3 says [1]:

   When fetching resources for an element
      The element's Document.

Is that supposed to be the element's ownerDocument?  Or something else? 
  The term seems to be underdefined.

It's also not defined whether the document is to be examined at the 
moment when running the fetch steps or at the "time convenient to the 
user and the user agent" when the download happens.  This might matter 
for, e.g. script that does something like:

   var img = doc1.createElement("img");
   img.src = something;
   doc2.adoptNode(img);

[1] 
http://www.whatwg.org/specs/web-apps/current-work/multipage/urls.html#fetching-resources