Oldmate, your correct. Something I didn't consider. The taxi fuel isn't co sidered in the MBRW for the flight becuase it's burnt prior to take off. Too much sugar for me today, damn rabbits!
All in all it seems it depends on what point of view your looking from. Managment may say ditch the pax and go, beancounters will definitley say that also, if your customer service orientated you'd say make a stop to get some gas.
The only down side is the bloody media got a hold of it and made a song and dance about it which amounted to bad publicity. In saying this I doubt very much if they decided to make a stop the media wouldn't bother reporting on it either so your cactus either way.
Well done lads, seems you made a good call.
Rocket