Is there any way that a calc error on the part of the airport staff can be traced after the fact?
That is very simple: A320/330/340 have a sophisticated system to calculate weights in flight derived from angle of attack calculations. Unless those computers were at fault (but this is very unlikely since the computers are all independant). The inflight weight calculation would not have prevented the accident but will be very handy to find out the problem.
As all the insiders here already found out that it was a loading problem, everything's clear. It could also have been a wrong input to the performance page (too high flex temperature setting) or just wrong reading out of the performance book (or laptop, whatever they use in Emirates).
Dani