However any load error during refueling would have been picked up by the A/C and generated a "> STAB GREENBAND" EICAS message which comes from the nose gear pressure switch during final prep indicating an error in any of the following, Loading, Weight, C of G.
As I pointed out in the closed Rumours & News thread, you won't get a message if your FMC computes an aft CG and actual CG is very far aft
The pressure switch check is a very primitive, not like a W&B System.