The wild boar population of the Pyrenees mountain range which separates the Iberian Peninsula from the rest of Europe has been on the upswing for the last half century. The growth in wild boar numbers is attributed to several factors including abandonment of many rural villages, lack of natural predators like wolves and milder winter conditions.
Wild boar are actually quite dangerous with a top speed of 35mph over short distances and sharp tusks on males that can inflict severe injuries. Attacks on humans are usually defensive in nature and occur when they feel threatened or cornered or are protecting their young.
Difficult to say what provoked this wild boar attack on a skier in the the Pyrenees but it seemed intent on taking the man down as it plowed through deep snow to get to its victim.
The best course of action if you encounter a wild boar is give as much space as possible to avoid an attack. If a boar attack seem imminent, seeking higher ground like climbing a tree or getting on top of a car is recommended. If no higher ground is available, victims should do everything possible to stay on their feet and use whatever is handy as a weapon to fight off the attacking animal.