I have no idea, but given his reported agitation and paranoia about his work, then this unusual sounding crash, it’s natural for speculation to arise. Who knows, maybe he was poking around Benghazi, given his prior history, or any number of other peculiar recent goings-on that would disturb even a leftist reporter who actually did still investigate?
Yes, at this point, it could be anything, including DUI or drugs or just plain speeding.