Naomi, if I understand the story of your friend in South Africa correctly, she is responsible for helping to spread AIDS.
Perhaps the organisation who sent her there bear some responsibility as well, because they did not make it absolutely clear to her that she would be dealing with an alien culture and explaining the way of thinking of that culture.
Do you really think that the Catholic clergy (and I am including the nuns here) in developing countries is comprised solely of men and women from the west who have no understanding of the cultures they are working in ? Or that those who come from the west are incapable of understanding other cultures and ways of teaching ?
Somehow, I doubt that you do. And if you don't believe that you must be aware that developing countries have plenty of clergy who come from their own countries, who do understand and relate to the cultures they come from and who are quite capable of explaining things to people from their own culture in ways that they CAN understand.
You are perfectly right about one thing though, we are not going to see eye to eye on this.