I'm not familiar with that race specifically, but it's not unheard of for a young rider to have massive strength, but little technical skill. The ability to descent and maneuver technically only comes with years in the saddle.
For example, the ability to bunny hop varies. http://www.cxmagazine.com/to-hop-or-not-bunny-hopping-cycloc... claims that, in Sven Nijs's case, it is to do with his BMX experience.
I couldn't find a good video from cycle-cross, but here is a nice example from road racing: https://www.youtube.com/watch?v=iPHnqI13vPk. Not everybody is as willing to take those risks and as good in recovering from (for him) minor mishaps as Vincenzo Nibali. Some cyclists are even known to take in a few bisons of water at tops of mountains because heavier bikes descend faster.