I think people in here might be overestimating the ability for the bank to find out where the money went.
I went into the actual branch and took some cash out from the teller and they overpaid me by $400. They had no idea where the money went, even though there are cameras inside the branch.
They would have never figured out where the cash went if I hadn't brought it back. They gave me a few hundred Air Miles as a thank you for being honest. (oh joy, air miles)
I was also friends at the time time with commerical bank manager there and he told me they wouldn't have been able to tell where the cash went. He said the teller that was out probably would have been fired.