When someone makes a mistake, use it as a learning opportunity.
A mentor of mine once told me about the employee who made a mistake that cost the company $10,000. He went into his boss’ office expecting to be fired. The boss asked a few questions and then said, “See you tomorrow.”
The employee responded, “I’m not fired?!?”
“I just spent $10,000 training you. I’m not going to waste it,” replied the boss.