Speaking from experience, you must be careful when you are winning because it comes with a lot of temptation to continue playing. Gambling has a way of giving you money and taking x5 back from you, this might include the money you have worked hard to get. Losing your hard earned money isn't really pleasant and it might ruin you mentally if it happens continually. It's important to take breaks from it when you are winning Because if you keep pushing your luck you might end up losing everything you have won .
Well from what I understand from the guy in the story, he is kinda smarter than we might think. The action of deleting his casino after realizing a huge win is kinda smart move. I know of few person who have made millions in one sitting and still loss it all to gamble. And making purchases could be a way of not spending the money back into gamble. So yes he might be addicted but not at a critical stage. There are chances for recovery. Knowing fully well that gambling can not be all that profitable, one can set a stop loss slightly above the initial amount he started with so that if he fall back, he will not end up exhausting everything. Though there are times where this strategy won't work, and that is when the better keeps losing from his first game till he finally exhausts his money for gambling.
But we know how the temptation from gambling can make us still sit in the casino and keep playing gambling after we win much money. We will not realize that if we win, we must stop gambling and leave the casino instead chasing more winning. Gambling can gives you the win and some money but if you don't realize when you must stop gambling, you will still playing gambling and not think about quit gambling. A wise gambler will know what he must do whether he lose or win and not trying to keep playing gambling if he thinks it is enough. He will stop gambling and not takes a look back because he knows that gambling can make him return and keep gambling.