Obviously, you cannot handle money matters if you have a problem with gambling because there's a risk that you will steal money from the company to finance your gambling addiction. There is already a lot of news related to that.
How can they steal the money? They are surely just processing numbers on their respective programs but they can't just release the money for their personal purposes like doing gambling. In a financial department, there's a processor, and quality checkers then the final decision will be the CEO to now process the money transfers.
And that person is risking losing the job and possibly being legally sued if they will do such things.