I disagree with the author. He is assuming everyone is using a matrix mode for exposure. And if all he is concerned with is properly exposing his subject in the snow, he should use a spot meter on his subject.
I also strongly disagree with his apparent propensity to overexpose in the snow. I shoot in the snow A LOT. And I am nearly always underexposing by 1-2 EV to keep from clipping highlights. It's much easier brighten underexposed areas of the frame than to pull details out of blown out highlight areas.