There will be innumerable systems that will behave in the same way. New 'orders' pull through the current contact details to populate some fields, but if the contact details are subsequently updated, the changes aren't automatically pushed down into 'open' orders.

It makes things a lot simpler when the contact details are held in a different database to the order system - I don't know how the BAEC (where the API is held?) system links to, or interacts with, the BA ticketing system.