Bluesafari,
I'm sorry but I can't provide you with a straight reference to this effect of lightning srikes on an aircraft.
Several years ago the local church spire had a large hole blown into the side by lightning strike.
It had been raining for several days and quite some water had been absorbed by the bricks it was built from.
When it was struck by the lightning bolt, the water in the bricks expanded at such a high rate, a 6 by 4 meter hole was blown out.
It looked like the spire had been shelled by artillery except that all the debris was ejected outwards.
Logic would dictate most of the current should flow along the wet surface, but it did not, casing the damage.
At the heavy maintenance base I used to work we would use a thermal imaging camera to find water ingress in composite panels.
When viewing the a/c shortly after it touches down, the frozen water within the composites showed up clearly.
Pls remember the mesh which is applied to the surface of these panels, is very thin.
I have seen a/c being masked in the spraybooth where the masking was cut with a knife, unacceptable of course, but it does happen.
The mesh is easily damaged in this manner and after the a/c is painted this breech in lighning stike protection is undetectable.
To which extent this affects the lightning srike protection I do not know but it seems logical for temperatures in the composite to be at their highest value at these locations. (in the event of a lightning strike)