now, I have a question, do you think the man is entirely at fault or someone should also be responsible?
Japan has some strict laws on gambling and its allowed to specific people under specific conditions. You cant gamble openly in Japan like you do in USA or Europe. The man shouldn't have used that money for gambling since in banking system you can easily be traced. So the man was at guilty since he did a crime knowing that he can easily be caught.
The truth of the matter is the man is guilty of using money that does not belong to him to gamble, this act is a criminal act, especially in Japan which has strict laws on gambling. The bank will trace the money to the man's account the only way he may escape jail is only if he is declared bankrupt, and given time to pay back even though it looks impossible for full repayments.