From David Gordon green himselfYou have a source for that? she literally implies hes supernatural in the movie
The suggestion that he is more than a man is a theory that Laurie has,” the director tells IGN. “My own personal concept for Michael, which will carry forward as long as I'm involved, is that he's capable of spectacular things but not impossible [things]. So I don't personally see him as supernatural, but I see the element of fear that he's generated and exacerbated is transcending the immediate character and moved on to an entire community."