I didn't really want to comment on this, so I won't speculate on the reasons why AF447 crashed.
However, what worries me is that it seems some professionals are really dismissive of the potential of lighning damage on modern aircraft.
I've read through all of the posts and it seems strange that no one has mentioned positive lightning, which account for less than 5% of all strikes.
Positve strikes are at least 6, and often up to 10 times more powerful than standard strikes. Modern passenger aircraft are not built to withstand positive strikes as the technology is not available: the discovery of positive lightning is pretty recent.
Positive lighning occurs when a positively charged leader forms at the cloud, and a negatively charged streamer issues from the ground.
Positive strikes can occur far away from CB (of course, originating in CB), due to their immense energy which can reach up to 300KA and would therefore far exceed the 20nm cordon recommended for CB avoidance for shear/turblence/strikes etc. Compare this to standard negative strikes of up to 30 KA and it is easy to see why these strikes are very dangerous.
For pilots who dismiss lightning strikes as almost harmless, well, you'd be right. Up to 95% of the time. It is unlikely to happen, but it can and has bought down aircraft, Pan Am 214 is an example.