He probably had been trying to avoid casinos and gambling for some time, but then he might have seen something that had refreshed the urge for gambling inside him, and that made him return to gambling. Such people would say initially that they won't do it like before, and will only try their luck or just play a few bets and stop, but we know they won't stop because if you have been addicted to something before, you stop doing it, and then you return to it, you are not returning to only try it but you are coming back totally.

Nothing can be done to handle such a situation if the person himself hasn't acknowledged the fact that they shouldn't be doing it, or maybe someone around them who can keep reminding them that they aren't supposed to get too involved, because then they won't be able to get out again. Other than that, if the person is on all his own, there is no stopping him if he gets too deep again, he is going to become the same person that he was before.