Your post made me think that that bank did not care much about that person and personnel in general. Few fails at work, caught gambling - got fired. In someway I think it might be more human to try to help that employee with his gambling. I dont think that bank fired him immediately when they saw him gambling for first time. I think there were talks, warnings before firing that person. If they see a person has problem, it would be best to help him. Instead, now he still had this gambling problem, and now he is jobless in addition. Bank made his situation from bad to worse.
If the guy didn't used customers' money then there was no need to fire him because that is what pleases him to do. That is his own choice. If he was doing his job well then there was no need fire him that was doing his work diligently. From my own understanding of the whole thing, the sacking of the Banker is beyond the gambling habit. Probably he has been borrowing from the.bank and using it to gamble and he has been reported and warned but gave deaf hear but when it was obvious and he was fired.
I suppose that people have wrong vision what bank is and how it works. I believe that people imagine it as a building with number of rooms, and a room under thick door where cash is stored. Otherwise what employee can be stealing then? In reality, everything is digitalized. Banks work with cash is very limited, and it is really hard to steal something without being noticed. If someone think that it is easy to steal from bank account or customers account, then you have never worked with banking program, never seen its UI. Everything is monitored, every little extra move is instantly alarmed and security get a warning and you get your working session blocked. If someone think that an employee can use any bank PC to enter banking program, and to make a transaction to any other account, then I suggest you to stop watching silly movies. Banking program for employees to make transactions is not like your regular private user accounts interface, where you pay bill and send money to others. And if someone think that employee can go to his bank colleagues, and they will open him a credit without bank noticing it, that is also quite impossible to happen.