Based on his behavior I would guess that he has bipolar disorder. Moving to Hawaii, going to Ukraine, all this other erratic behavior in the past, all sounds like mania. This was probably a manifestation of delusions of grandeur. If he wrote out an explanation beforehand it will probably be complete nonsense to us that made complete sense to him at the time. If he didn't give an explanation beforehand, it will probably be impossible for him to explain his reasoning after the fact.