ELAC is right. Nothing has come out about an accidental jettison of fuel. That's an extremely unlikely scenario. My theory goes like this. Line chafing caused a fuel leak on the engine. The engine keeps running 'coz the boost pumps are supplying adequate pressure to feed the stove at CRZ thrust as well as feed the leak. It's dark outside, so the pax don't see the fuel vapours. First thing to get noticed is an ECAM advisory for fuel imbalance as that tank gets light. Crew get out the Fuel Imbalance checklist. Although the checklist provides a caution that balancing is not to be performed if a fuel leak is suspected, the crew, unsuspecting, carry on and open the crossfeed and turn off the boost pumps on the light (leaking) side. Tank redundancy is lost and all the fuel can now go overboard. Unfortunately, ECAM (nor the FM)don't warn the crew of a leak. That has to be noticed by the crew during their fuel monitoring process (amount at start of trip minus amount burnt by engines should equal what's left). The FUEL LEAK (paper) checklist is quite specific about keeping the crossfeed closed to prevent a leak from affecting both sides. It's very likely that the crew never got to that checklist, as the engine flamed out, probably due to a reduction in fuel pressure due to the crossfeeding or worsening of the leak. The ECAM ENG FAIL warning would definately have diverted the crew's attention away from the fact that they were still crossfeeding fuel from the good side to the leaking side. After unsuccessfully trying to relight the engine, they descended and planned for a diversion to the Azores, probably still quite a distance away. With the engine shutdown, the leak is no longer an issue. The crew may have figured out by now that the fuel situation was critical and perhaps had closed the crossfeed, but too late. The next realization that all was not well would have been the first ECAM WING TK LO LVL message. Then the other one. Then silence. Sound plausible? All will be revealed by the DFDR, QAR and CVR in due time.