1099 for retainer paid to an attorney

Our company paid a $5,000 retainer to an attorney in 2019. We issued a 1099 reporting $5,000 in box 7. The attorney received the 1099 and asked us to issue a corrected 1099 showing $0 in box 7 because the $5,000 retainer is going to be refunded, but not until 2020. Is a corrected 1099 for 2019 appropriate? How should this be reported correctly?

 

Thanks!