Having dealt with the 340 for 8yrs and quite a few lightning strikes, I would be very surprised if this was the cause. You usually end up with a splatter of entry marks and a burn area on the exit. I did see a photo from somewhere of a fixed nose u/c door with a hole in it, but on a 340 that is the worst I have seen. Certainly never heard of loss of electrics in a ny shape or form.
Also if complete electrics were lost the alternate braking (no antiskid) should have been available as it is a fully hydraulic backup, and all the static inverters and other backups should have come online, however this incident may have happened so quickly that there was little time for an considered reaction and the pilots reacted to what they saw. Well done on doing what they did. So whatever the cause it is all speculation at this stage.
Also this is not the first A340 crash, Virgin Atlantic had one in '97 with an main gear leg stuck up. Certainly looked like a crash from where I was stood, but again saved by good flying skills. So with 2 accidents in 14 years I guess that safety record will not look as good to the press now, look what they did to Concorde over 1 accident!!!