It is just pure luck that he was able to guess it right and would be even more lucky if it is his first time to try it. Gambling really is easy money but you need risk management as well so that you can limit yourself in case there will be losing streaks. In this game, you have 6% chance to guess it right and he is lucky of winning it but if he was in a loss more times than he won, it is still a loss but at least he get the feeling of being happy and proud of getting it right.