its really a buisness law question

you Sheila worked as a executive assistant in office of a law firm operated by Attorney Doug Jones. She suggested that the law firm become involved in class action litigation involving a major drug company. Attorney Jones agreed to become engaged in the cases as she had suggested. The law firm earned millions of dollars in attorney fees. Attorney Jones promised Sheila that she would receive a bonus because of her efforts and hard work. Sheila, her husband, and Attorney Jones met to discuss the terms of the bonus. Attorney Jones orally promised to pay Sheila a $500,000 bonus in 18 monthly installments. The promise was not in writing. Unknown to the attorney, Sheila had secretly tape-recorded the meeting. After paying Sheila $28,000. Attorney Jones stopped making the bonus payments. Sheila filed a lawsuit against Attorney Jones to enforce the promise he made to pay the bonus. Who wins this case? Be sure to fully explain your response