Actually, that's totally not what he says at all. That is one confusing article. Factual errors aside, he never makes an argument as to why Andy won't win a Slam. In fact, he says that the top four are even money at the AO. The only argument he really makes is that Muzz shouldn't be the favorite going into Melbourne. Uh, ok.
Anyway. I think Steve's just trying to be contrarian. Methinks his heart ain't in this one.