With more eyes on Hamilton, it could also be more likely that he would avoid alcohol. He managed to avoid the booze after losing Game 6 and 7 of the World Series. I think he has some willpower.
Greinke isn't an alcoholic for all we know, so if he went to the pub after a game, I don't think that would be a big issue. Besides, who the f*** are you to claim familiarity into the lives of these two men? How could you possibly know what their triggers are, and what they consider stress to be?