I re-read the original thread in conjunction with the AAIB report and it appears the bulk of the 'speculation' was correct - if somewhat difficult to believe.
It is miraculous he made the previous trans-Atlantic trip successfully. It is difficult to do this low level (i.e. staying out of Class A trans Atlantic airspace) which he would have needed to do to be legal. Given the casual approach to regulations, it is surprising he didn't just file IFR and go, after all the weather system was relatively thin.
estimated to have been between 2,000 ft and 6,000 ft amsl, with other isolated layers of scattered and broken stratocumulus/altocumulus clouds between 6,000 ft and 13,000 ft amsl.
(my bold)
I remain staggered at the whole decision making process of this flight.