I would fight shy of contesting the science; complex data models aside it seems to pass the 'pub logic' test (if by closing time a pub full of people at least agree to disagree it's probably OK). So although continental summer thunderstorms are seasonal, I'm willing to conceed that the fithy night might have been influenced by more than just the usual factors.

However, as usual the hype seems to be that the battle was for the genius Napoleon to lose. Then commences the grasping at straws, from haemorrhoids to the precipitation. The slightly more likely possibility, that the Great Man got beat on the day (either by circumstances or opponents) seems to escape them. Well, it sells books and makes cheap publicity for hard up research scientists I suppose.