What I want to know is: Did I do a good job by using gambling to save him? Or do I just make him have an interest in gambling as a source of income?
You did the same mistake as him. He could have used that money to buy whatever he could for his family but he instead chose to gamble.
You could have gave him whatever you could so that he could buy food for his family but you told him to gamble instead.
Now the next time he would be in the same situation he will gamble again instead of buying food directly.