This was done when he was checking the cards.
He had purposefully checked the cards in front of the two men and had accused them of cheating before because he wanted to confuse them and distract them. In the end, he succeeded as the two got angry at him and ended up being distracted enough to not realize that Hecathe was fake shuffling the cards.
This was clearly cheating, but why should Hecathe care since he planned on winning?
If one wanted to enjoy the game, they would play fair but if a person played only to win then wasn't cheating a needed method to ensure that win?
If the two before him were honest men then Hecathe would have thought a couple more times before deciding to cheat but since they both had the same untrustworthy brain cells, the decision to cheat wasn't hard to make for Hecathe.
The first round was announced and the player placed their cards on the table one by one.