It's not BA but having recently done AKL-PPT (Auckland to Tahiti) sub 5 hours departing around 7.30pm and arriving 2.30am (when everything is shut) struck me as possibly the worst flight time planning ever (and with meal service, landing prep and a tail wind, next to no sleep opportunity).

Its just bad for absolutely everything and could easily be pushed back 2-3 hours to make it far more practical.

The return departing 4am arriving mid-morning AKL is also utterly crazy.

Still, I'd do it again, as really it's the destination and not the journey which matters!