Imagine you make a very complicated calculation in excel for a client who is going to make a decision. After you reviewed it a couple of times you notice you are going to save the client $10 million in taxes. You give it to your senior and your partner, who review your work. They agree on your calculation and tell the client about the tax savings and the meeting to finalize the transaction is tomorrow. It's 9 o'clock at night and you are finalizing the paperwork, and you suddenly realize you made a careless mistake on excel and instead of putting a minus, you put a plus, so the client is not going to save $10 million, but is going to owe $10 million. What do you do? How do you handle the situation?
