This odd factoid has stuck with me through the years, so finding myself in the southern hemisphere, I decided to check it out. And yes indeed, the water does seem to be draining in a counterclockwise direction, the opposite of the way it flows at home.
Still, I thought maybe this was a fluke, so like any modern person who occasionally has access to the Internet, I googled it. Turns out, this question is one of scientific debate. While water should flow counterclockwise in the south and clockwise in the north (a phenomenon known as the Coriolis force), the direction is due more to the configuration of the sink than anything else.
In other words, perhaps I observed the Coriolis force ... and perhaps I did not.