Solution: flight deck warning of all unlatched access panels or doors that could hazard the aircraft if left unfastened, unlatched engine cowls are the most important, why Airbus is still ignoring this recurring issue is a mistery. All incidents of this type have occurred despite multiple visual checks by engineers and pilots, clearly a misleading design which must be fixed asap.
Sorry, but that's not the way the world (and the regulators/manufacturers) work.
The comparison with the DC-10 cargo door is a good one. Yes, the cowl latches will be redesigned, but only once the current design has killed a planeload of passengers.
Today's incident hasn't changed anything, it's just another statistic.