There is an AF pilot in one of the papers today claiming it "has to have been" a bomb, because "I have been flying these aircraft for 10 years and a lightening strike would not bring one down". He also mentions the bomb threat received a few days before which caused a 2 hour delay whilst the aircraft was searched, although he acknowledges that this was on a different route. The pilot wished to remain anonymous - I wonder if that is because of the airline's previous MO for dealing with pilots who speak against the party line following an incident, or if the paper is just making the whole thing up.
Either way, as has been mentioned elsewhere on this thread, the airline were unusually quick to come out with a likely cause IMO.