LOL, probably they can call their stupid god like casting bad words when gets loss or it could be also calling the real god when things gets good or bad. It will just depend on the scenario.
But, I do not really believe atheist has no God at all. They just deny the religion but no one could not feel a high beings with super powers that created the world and the human beings on this earth.
The first statement was right, it's all depends in the situations where you are in place, calling god to help you by doing a sinful act very funny, when you win you'll be thankful but if you lose then you will assume to yourself that there's no existence of such being and you will keep denying it inside of you, mentioning being atheist, maybe it's normal to say that you probably looking for someone to blame if things will not favors you.