Hi jaylem,
Your customer may have been correct, because there is a feature called "Call Transfer Disconnect"(Pacific Bell), that is available on a per line basis that does just that! It is the 3-Way Calling feature with the "transfer" part added. Some service providers may call it something else and is available in 5ESS & DMS100 switches. You will have to check with the service provider to see if they offer it.
Hope this helps!
....JIM....