I could be wrong here but aren't there fairly restrictive caps on the number of seats available between LHR and Japan? I seem to remember VS being restricted to an A340 on the route a while back because BA were already running 744s on the NRT route and another 744 would have bust the limit. If thats still the case its quite possible that they wouldn't have been allowed to sell the seats on a scheduled flight basis anyway. Besides, there were probably only 50 hacks on board anyway, the rest of the seats being filled by BA managers, analysts and e-working outreach executives on fact finding trips and product evaluation duties.