Although at their first ESPN event (ironically at Osceola Stadium in Kissimmee, FL) in a key moment of the championship cornhole game the partner picked up the bags before the last bag was thrown and there was a lot of controversy.
Also a player can foot fault.
But for the most part no referees.
When my brother first started in cornhole he was just a player in a local bar league and there was a nasty fight where one player punched another player and the player fell and hit his head and there were legal ramifications etc.
So yes people can ruin anything.