Miranda ordered fifteen black shoes from Steven to sell in her store on June 20th. On the day of the delivery, Steven discovered that he only had fourteen black shoes. He added one set of dark blue shoes to the delivery. Steven believed the dark blue shoe would be acceptable because he had delivered dark blue shoes instead of black shoes in the past and Miranda did not seem to mind. 

An hour after the delivery, Miranda noticed the dark blue shoe. She called Steven and asked him to exchange them for black shoes as those were the most popular. 

Must Steven cure the defect that day?