I can't believe that the handful of long haul flights could not have been termporarily accommodated at T5, this would have been a far better short-term solution to the problem and would have kept all First & Business Class flyers happy (well after the T5 problems were sorted anyway). Anyway, sure this was covered on previous threads (to death no doubt), but Qantas don't use BA staff at T4 any more, so probably more complicated than first thought....
3 flights on BA/Qantas to BKK
4 flights on BA/Qantas to SIN
1 flight on Qantas to HKG
(missed anything?)