Indirect self-plagiarism?

Of the matter of the retraction of Nayernia group paper published in Stem Cells and Development on 8 July 09, the journal Science gave details that the plagiarism in question involved a word-for-word discussion of prior Nayernia group work taken from a review article by Makoto Nagano of McGill University in Montreal that appeared in Biology of Reproduction.

Why would research group X plagiarize a discussion of group X's work from author Y? This is a sort of indirect self-plagiarism. Had group X merely summarized and cited their own past work, there would be no problem at all.

The text from Science: Surprisingly, [editor Graham] Parker says, those introductory paragraphs describe previous work done by the authors of the new paper, raising questions about why such a passage would be plagiarized.

See also
British science paper on "sperm from stem cells" retracted!.

***The bioethics blog bioedge alluded to the overselling going on in the initial paper:

Although the original paper referred to the production of "sperm-like cells" with "tail-like structures", its journal title, and the university press release discuss "human sperm". No doubt the next journal to review the research will examine the words and the work a bit more carefully.

The Newcastle group is planning to submit the article again:

According to Nature News, the University of Newcastle says that the paper's original first author, Jae Ho Lee, was responsible for the plagiarism and has apologized to the authors. He has since left the university. "No question has been raised about the science conducted or the conclusions of the research," says the statement. "The name of Dr Lee has been removed from the first authorship. The paper will now be submitted to another peer-reviewed academic journal."