And in those situations, the bank definitely, always wants its money back. When I was in college in Washington, a bank mistakenly put 20s in the 10s dispenser in the ATM machine. My friends and I took out a bunch of money in a way that got it to dispense 10s (which were really 20s). We thought we got over on the bank. We learned a couple weeks later, when there were extra debits to our accounts, that we did not.
Oh ya. They have a way. Easy to trace too. It may have been their mistake but it was also their money. No excuses.