NO WAY! The main reason is, it's dishonest. Secondly make no mistake the bank will not let you get away with it. In the US, your sentence for bank robbery is tougher than killing someone in some cases. And that's what it would be like, if you spent the money, bank robbery. They would not even consider it their mistake, but punish you to the fullest extent of the law. So again, NO WAY!