But as long as players form the prize pool from their own contributions, they also determine the rules of the game. It's no coincidence that most tournaments have a rule: "players can, by mutual agreement, change the rules of the game." In the cases described, there was an extended interpretation of this rule.
For example, in the tournament organized by Nagan, he was the sponsor, so he had the right to change the regulations during the tournament (within reasonable limits). And since the players didn't object, it means that his actions were within reasonable limits. In his place, I would have acted exactly the same.