The number in the article comes from a rapid mortality surveillance system created by the South African Medical Research Council to monitor trends in mortality without a substantial time lag. You can see their report here. I don't know enough to comment on the reliabiity of the number.

Anyway, my point is that mortality rates in South Africa are improving rapidly with increased availability of antiretrovirals. That trend is corroborated by other sources (see page 6 of this Stats SA report, for instance).