I will comment on this, based on my aviation experience
(18,000 hours as airline pilot, possess a aviation mechanics license -A&P, certified flight engineer, and served on 6 crash investigation teams).
First: Airbus has a history of misleading the public. They
MAY be trying to shift blame away from an aircraft failure. This would be a case of the foxes guarding the hen-house. Airbus and French credibility is very low.
If the aircraft hitting the water intact is true, there are only a few scenarios.
** One is that all flight computers failed and the pilots became unwilling passengers of an uncontrollable airplane. This is unlikely, but could have been caused by one or more massive lightning strikes. Aircraft get hit by lightning frequently, but usually with only minimal damage. This would probably involve a total electrical failure, including all generators and batteries.
IF Airbus and the French Gov't wanted to protect their interests they would avoid this finding.
** Another scenario is that the crew was unconscious. How could this happen? Either by violence, loss of pressurization or by inhalation of a dangerous substance. The loss of cabin pressure as a cause is unlikely because the crew has "quick donning" oxygen masks and they are well trained in their use. A slow loss of cabin pressure (un-detected) has caused a few crashes because the crew did not know to use oxygen. This would mean a failure of the cabin warning systems and the automatic deployment of the oxygen masks. For both things to occur at the same time would be unlikely. This would also need the autopilot to be disengaged or unpowered. If the autopilot was functioning the aircraft would have continued flying until fuel exhaustion. This would have happened somewhere over Europe, hours later than the crash. Sabotage and human mis-deeds would have have to be considered.
*** A suicidal pilot took control and caused it to happen. There is precedence for this scenario. Air Egypt flight 99 crashed after takeoff from JFK because the co-pilot caused it by intentionally flying into the water. Terrorists threatened his family unless he complied. Egypt has continuously denied this happened, to protect their self interest. The US Gov't down played this because we need friendly Arab countries to continue supporting our efforts in Sandland.
http://en.wikipedia.org/wiki/EgyptAir_Flight_990
The black box (flight data recorder) would only record data while powered and receiving data. If there was a total electrical failure, bomb or some other cause of an inflight breakup the Fliight Data Recorder would probably not contain useful data. The last data link transmission that reported problems with the air-speed indicating system was the last minute the plane had electrical power. As long as power was available the telemetry would continue.
IMO you can expect a French finding blaming something other than the airplane as the cause.
The use of multiple parts vendors worldwide is very common should not be a cause of concern.