Yeah, it's the best solution for him to re-assess whatever mistake he made during that failed session, instead of pushing his way to keep playing and most of the time the outcome will be against him, you need to be wise to keep that emotion and treatment towards your gambling participation, having that kind of understanding will let you to keep yourself in shape.
By introspecting ourselves on the mistakes we have made before, this will certainly motivate us to be more careful in every decision and action we take in the future. For wise and responsible gamblers, have good thinking because opportunity does not come a second time and this can be applied in gambling so that we remain consistent in maintaining good control.
Mistakes is the best teacher , but that is we know how to admit it and use to be our guidance in next decisioning because there are mistakes that have been used as bitted way and instead of admittance being used to be in negative ways.
Gamblers must know when to stop and when to start , and also know how much to lose and how much to win and that is what being responsible means.
When the gambler has an overall idea of his gambling he can control it. A gambler can exercise self-control if he can pause his gambling at any time, regardless of his condition. Unless the gambler knows when and under what circumstances to stop, or can control himself at that point, even if he wins from gambling, he will fail to keep the winnings. In gambling many may win but not everyone can keep the winnings. I think self-control is a good quality of the gambler. Those who possess such characteristics must be able to engage in responsible gambling.