They mention it in the article and couldn't come to any conclusions.

  I don't see anything that stands out as saying these couldn’t have been written by the same person (especially separated by a decade),” he wrote. “Nor do I see any similarity that wouldn’t also be true for many other authors and codebases. At a minimum, however, if they were written by the same person that person’s styles changed a lot (either due to time or intentionally hiding them).