Here's the proper mindset, if we are to give money back to someone who lost that money, we'll just pushing him to let that money be lost again, for sure it will not help him so we should consider other ways such as providing betting advice and to help him earn and control his money to not be bet all in all in gambling.
It's okay if he will stop gambling after we give him money but most gamblers does not think and do like that, if they have some money, they will still gamble again thinking they can win back all their loses, it's kind of an unrealistic mindset that will only push their to a more disastrous life ahead. if we are a true friend or if we really care, we won't tolerate, let them learn from their mistake.
Even if he loses the money, he will search the other people so he can borrow the money again. He will do that over and over because he is addicted to gambling. That is sad because that person cannot hold or control himself in gambling, and that will only make him search for money for playing gambling. We cannot help him by giving the money because he will use that money to play gambling if we don't know.
