I am still wondering, what could possibly lead a person back to gambling after successfully quitting initially? Know well the reason for initially quitting was addiction, does it make sense to go back to gambling and become even more addicted?
First of all it is needed to figure out why originally a person became addicted to gambling. Because of desire to get more money, endless process of trying to win back what were lost, or a person loves to gamble in general. A person can return after quitting for various reason. I would name improvement in self control as a first one. If a person has learned how to stop himself from doing something he dives completely, then I see no problem to return.