Have you seen this: http://fileformats.wordpress.com/2012/12/30/openoffice/ ???
(I'm cc'ing the author of that blog post, Gary McGrath) This is from the perspective of a person interested in long-term preservation/archiving of documents. This looks like a feature that is working "as designed", although it does obscure the fact that the image is linked, not embedded in this case. It might be worth having a web page, or a document, about best practices for creating documents in OpenOffice that are free of such external dependencies. Could probably also use the ODF Toolkit to scan documents to identify such issues in a document. Regards, -Rob