I think the wording of the law is very broad, and "marked cards" is only one of the conditionals listed. Since you seem to be taking a very strict definition of "marked cards", other conditionals of the law were also met:

> Knowingly to deal, conduct, carry on, operate or expose for play any game or games played with cards, dice or any mechanical device, or any combination of games or devices, which have in any manner been marked or tampered with, or placed in a condition, or operated in a manner, the result of which tends to deceive the public or tends to alter the normal random selection of characteristics or the normal chance of the game which could determine or alter the result of the game.

Specifically, it seems like the cards were "placed in a condition" and "operated in a manner" which "alter[ed] the normal chance of the game" for Ivey and Sun.