One of the most-important works ordinarily attributed to Eric Blair (ok, he was using the Orwell name by then) is Emmanuel Goldstein's Principles of Collective Oligarchy. This document appears at the core of 1984, but it is written in a rather different tone and from a distinctly different perspective than the remainder of the book. Would a computer program trying to discern its "authorship" agree that Orwell wrote it, despite all of the steps (word choice, argument method, etc.) that Orwell took to make it authentically "not his"? Then there's the whole Borgesian question of Don Quixote's authorship… in the twentieth century. At the metaphysical level, we need to ask whether it really matters. Certainly in St George's case, which involves multiple levels of invented auctorial personae in a single work (and, in fact, in a complete body of work), this is a nontrivial metaphysical question. Is the "Eric Blair" who was hired by the BBC to make wartime broadcasts to India and Burma the same "person" or "author" as the "George Orwell" who wrote 1984 and Animal Farm and "Politics and the English Language"… and Principles of Collective Oligarchy? Does it matter? And does it matter for purposes of copyright? Recall that pseudonymous works have a different term of protection than do those attributed to their natural authors. And this is before we get into collective and group-effort works like popular music and film.
Actually, I don't think the inquiry is ridiculous. I'm not too fond of the method that's been chosen by the researchers cited in the article; adapting one's technique to the subject matter, materials, and anticipated viewing environment is, after all, one of the marks of true mastery of the arts. Just compare the rhetoric in Animal Farm with that in 1984! Then there's the whole unanswered question of how to treat authorship of a forgery; it's a question that eventually consumed a thousand pages of an unjustly neglected novel (not by me, but one should read works assigned in class). Reflexively, the question does have some interesting implications for and explanations of the development of copyright law, both in the US and overseas; but that, too, is for another few thousand words and few hundred footnotes.