If you give assurances to a 3rd party that a staff member is no longer on a 90 day trial period you do have to heed that. As an employer recently found out when they tried to terminate under a 90 day trial following giving assurances to a finance company the staff member's trial had ended. Read more here :
www.employers.co.nz/waiving-90-day-trial-news-oct-2024-newsitem.aspx