That Oddie but Goodie from Wesy Drayton in the 80s is still true. I'm also a retired ATCO and when returning from holiday earlier this year, the wife and I were told by the company that our flight was delayed by earlier ATC problems. The captain, bless him, though was an honest man and admitted our delay was because his aircraft went tech and it took a while to transfer pax and baggage to the backup.