That will be a wrong mindset if he still persists from his losses because he can losses more than he can imagine. Once that is happens, maybe he will not be able to hold on himself and will do something that can makes him bad.
He should realize that he just waste his money without have a big chance to win from gambling so it is better if he quit gambling and walk away from the casino to calm down himself. It doesn't give him benefit if he stays for a long time in casino just hoping to win from gambling.
In this matter, you have a lesson not to do the same thing like him. You should control yourself when playing gambling so you can quit gambling when the situation not good for you.
If the fellow had the intention of gambling for fun alone, there was no way he could’ve allowed himself to get to the point of losing that required or pushed him into chasing his losses. It was obvious that his pursuit for profits and his greed both contributed to him repeatedly losing and losing continuously which has landed him into lose chasing which of course rather than recovery still landed him into more losses. It’s just really unfortunate that how gamblers approach gambling with such a flawed approach and mentality, and find it even harder to quit even when they’ve repeatedly lost badly.