background to the Pope's words.
He puts forward the argument that it is not condoms themselves that are intrinsically evil but contraception, and that therefore the use of condoms as a prophylactic against HIV/AIDs can be justified. As he rightly points out, this has been an argument proposed for some time by some Catholic moral theologians. (I am not sure that is can be rightly described as the "consensus".) Back in 2004, Austen Ivereigh commissioned Fr Martin Rhonheimer, a priest of Opus Dei (and by that very fact trusted by many orthodox Catholics) to write an article for the Tablet in which he argued that the use of condoms by people with HIV/AIDS would help them to keep a sense of responsibility and that the use of condoms by a man with HIV when he has intercourse with his wife may be permissible since the contraceptive effect would be an unintended side-effect. I presume that the argumentation of this article and that of similar moral theologians underpinned Jack Valero's comments on television at the time of the Papal Visit that "the Church is not against condoms" in the sense that the Church does not oppose condoms per se but promiscuity and contraception.
Luke Gormally replied to Fr Ronheimer's argument concerning the use of condoms in marriage where the husband is HIV positive in Faith Magazine: Marriage and the Prophylactic use of Condoms
Austen Ivereigh remarks that he had to deal with the "fallout" from Cardinal Lopez Trujillo's remarks on the BBC Panorama programme to the effect that condoms were ineffective in Africa. In fact, as we know, on a national scale, this is true. Those countries which have strongly promoted condom use have experienced a higher rate of HIV infection whereas those who have promoted changed in behaviour have significantly reduced rates of infection. It should also be noted that the BBC programme "Sex and the Holy City" was one of the most notoriously biased programmes made by the BBC and was the subject of a chapter in Robin Aiken's book Can We Trust the BBC? which was supported by the scholarly critique by David Kerr. (Both Kerr and Aiken were long-time BBC employees.)
Some Cardinals, though accepting the large-scale picture, were concerned with the casuistry of individual cases and the public perception of the Church as inhumane and heartless. Austen Ivereigh lists among these, Cardinals Murphy-O'Connor, Danneels, and Barragan; and notes that other Cardinals (presumably including Cardinal Trujillo) disagreed. This disagreement was in 2005-2006; a commission of moral theologians was set up to look into the question but nothing was decided. In 2008, Austen Ivereigh spoke to a "senior official" at the Congregation for the Doctrine of the Faith who told him that he agreed with "clarifying" the teaching but that they feared the headlines that would result.
In other words, the story is one of division within the ranks of officials at the Holy See with factions both for and against a "clarification" that condoms could be morally permissible as a prophylactic against HIV infection. It could reasonably be assumed, I think, that the current direction of L'Osservatore Romano would be on the side of the clarifying faction and this helps to explain why the paper broke the embargo of the Holy Father's interview, publishing various extracts including his comments on condoms and HIV, thus ensuring that this would be the principal story in the world's media.
For the sake of further "clarity", let me say that the opposing faction would not necessarily have disagreed that in theory, in an individual case, the use of a condom by a homosexual man in order to reduce the risk of HIV infection would not ipso facto contradict the teaching of Humanae Vitae which was concerned with contraception. They would have been concerned that any signal to the effect that condoms were the answer to HIV/AIDS would exacerbate the problem in Africa and elsewhere - a claim that all parties accepted was "backed up by the evidence."