Hindsight is ALWAYS 20/20 but I'm curious about the info. provided to the crew by the FMGS during all of this.
On a Honeywell fit I can think of at least two pages that show EFOB at dest. (FLT PLAN & FUEL PRED). On a typical 7 hour flight that number might vary by a couple of hundred kilos (depending on the accuracy of forecast winds, amongst other things). If fuel was leaking at a rate of 550 lbs/min (250 kgs/min) as mentioned earlier then I would have thought that the EFOB would be reducing at an alarming rate whilst ETA would remain the same. If it's going to take the same time to get somewhere and fuel=time then something's not right.
To confirm what has been mentioned earlier fuel imbalance ECAMs are at hopelessly high levels thus only telling you that you've HAD a fuel leak. Also the Trim Tank Transfer System for CG management can obscure any imbalance by transferring fuel forward from the trim tank asymmetrically!!
As has been said so many times before let's see the final report.