The amount won does not help but the psychological impact does. It boosted his confidence in dealing with the company's problems resulting in more rational thinking which leads to an innovative way of solving the company's problems. As a result not only did he solve the crisis but even make his company even greater. Motivation at its finest.
I doubt about this idea. You can obtain a lot of dofamine through another activities which do not means to risk with your own money.
And of course, Smith could lose his 5000 dollars and then jump out of the window. Much more probable outcome than such "success story".
True every story has its counterpart if the result is different. He might end up selling his company if he goes out of that Casino empty-handed and depressed.
Because of that you shouldn't use casino as "motivation center"