Composites and lightning discussion (extracted from AF A330 thread)
Speculation - even in some cases here, informed speculation - is just that. However, as a general comment - and not connected to this tragedy, journos - the TWA 800 tragedy in 1996 caused a review of aircraft designs related to fuel tanks, hence FTS/CDCCL (and SFAR 88). One of the considerations was/is, of course, lightning as well as on-board causes such as compromised or ageing sytems, bonding, wiring or tank components (it is a very complicated subject). Bonding is fundamental to protection against electrical faults and is sometimes more difficult to assure with composites.
SFAR 88 and equivalent JAA/EASA documents required TCHs to assess their designs with respect to ignition sources. This spawned a whole raft of ADs and requirements such as training for those involved in continuing airworthiness functions (including maintenance), the need to maintain design characteristics (in maintenance, maintenance documents and planning functions) and the need to adhere to approved data when maintaining and planning maintenance.
(For example, as part of the assessment required under SFAR 88, some arc-testing on fuel tank components related to FQIS revealed that components passing 2000v arc tests when new arced at less than 50v when over 30 years old).
To iterate: a general comment only. Let's wait for the official report.