Likelihood is that most of the spare seats in Business and First on Long Haul flights go to BA staff who are on their rebates. Nothing more galling than having paid monster money to travel up front to get a numpty's mother next to you who tells you all about how little junior is doing well in the accounts department!
I'm sure GB/AD could re-look at the whole area of staff travel schemes and benefit in kind as I know of a family of a junior BA employee when all 4 were upgraded to first on their return - equated to about £12k in value. How can this be justified?
As they were upgraded it prevented any of the fare payers having the opportunity. just think of the marketing/goodwill factor lost.