This is rare, a gambler will always get back to gambling or allocate a portion of his winnings so he can continue gambling and try to extend his luck, but the guy choose not to continue and spend his winning to what's important to him, those who know when and how to stop when winning are really winners in gambling
it is not rare because he is not a addicted gambler mate so it is easy for Him to get away anytime he wants but the question is how long he can handle this decision?
because as i see this things are only decided because of the huge wins and he wants to spare Time and money with Love ones and other stuffs in real life but once he got established those things?for sure he will come back and bet againa s now he has already good amount to make a bet at any time he wants.
Why talking about rare things while we can call it normal since even though he is not a addicted gambler still hes mind will possibly find those winnings again. And let's cut the crap about the story since the main thing here is as you said how can he handle the guts on not to play since for sure the temptation to play is there since he have huge money from his winnings that he can spend to play again in his games.