On Monday, Valve released a fix for CS:GO that eliminated the smoke bug that caused outrage the day before. G2 player Ilya «monesy» Osipov used a trick on the map Mirage, which allowed to make an enemy smoke screen partially permeable. This is evident in the footage of the G2 vs Imperial match: when monesy throws the grenade, its area of effect overlaps with the opponent's veil, making it viewable in one direction.
Despite the fact that tournament organizer PGL had previously explicitly allowed the use of this type of smoke grenade, the tournament participants, through the CSPPA, agreed not to use it. Many agreed that such mechanics should in principle not exist in the game, regardless of how they manifest. This is not the first time a situation like this has arisen at a major and the tournament participants have come to a gentleman's agreement. For example, at the 2017 PGL Krakow, players similarly agreed not to use «the jump bug», discovered by BIG during the event.
Now Valve has released an update in record time that eliminated this smoke grenade bug. It can be assumed that the rest of the major matches will be played on the new version of the game, which means he can't show up either accidentally or intentionally.