Anyway... regardless of how this happened, the reason for it happening is easy: Gambling addiction.
People steal other people's objects, rob their own family, sell cars and houses to have money to gamble, so why wouldn't someone with "easy access" to other people's money do the same to support their addiction!?
Surely the elderly were reimbursed by the bank, and this employee should be duly punished, but he probably doesn't have the money to pay compensation or a fine.
Yeah, someone who has accessed to someone's fund and they've seen the disadvantage of these elderly that they might be forgetful about their funds and resources has been taken advantaged by the teller. It's for sure that the bank have done a legal action together with the victims so that this teller will learn the lesson the baddest way and shouldn't take people's hard earned money easily.
The bank's policy into hiring recruitment for sure have also became stricter and they'll read and learn the background of their future employees if they have been involved with gambling or any related kind of activities so that they're not only protecting their company's reputation but also the welfare of their customers as well as their funds. Because it's about the customers that they're working with and the customer satisfaction is what gives them the kind of living not only for the company but also to its employees.