[Ruberik]

I think it's fair to say that programming contest winners are exceptionally good at cranking solutions out fast; but they could be just as good at working reflectively in a team as everyone else, or even better.

The author of this article appears to think that he or she has provided evidence for the sentence you quoted, but a number of comments in this thread have pointed out that isn't what the evidence says; so the quoted sentence is simply speculation.