It looks to me that he is doing it to avoid putting a paddle in the blue boater's face and stay upright at the same time.  That is a single shot and may be misleading but I couldn't argue that wasn't done out of concern for the blue boater's safety. 

I wasn't there and don't know the boaters or care who won that heat.  I have to question the sense of putting 3-boaters in close quarters in a rapid like that.  Sure it is a race but you have to realize that incidents like that will happen in that sort of competition.  Why not just have them race separately to see who has the best time?  Better TV?