A more serious mistake occurred when the pair seperated. Once out of sight of each other the skier did not know what had happened to his friend until later when he found the dog. By the time he reacted it was too late. A more serious clue indicating they stopped thinking avalanche were the snow conditions. The skier kept breaking through into sugar snow and getting stuck in the loose snow.
Sugar snow topped with firmer snow are two key ingredients for slab avalanches.
Had they been thinking avalanche they likely would have recognized the snow conditions meant avalanches and stuck together and always traveled in sight of each other. Had the skier witnessed the avalanche he likely would have dug his friend out in minutes. The outcome could have been different. Travel in avalanche terrain means never letting your guard down. Little mistakes like different ascent and descent routes, or temporarily separating from your partners may not seem serious, however, in terms of avalanches the consequences of these minor actions can be deadly.