Winners have to submit code most of the times. There are sporadic computer vision competitions where it is possible to hand-label (such as geo-int competitions where people reverse engineered the flight paths), but vast majority it is impossible to hand-label. Nobody becomes a grandmaster without applying world-class machine learning skills.

The "cheater" in this competition is both a world-class data scientist and a reverse engineering hacker. Heck, people used to write papers about how they crawled the ground truth. Now they see their name in the newspaper.