Well, if Trump were subhuman on account of his severe psychological and cognitive disorders (e.g. malignant narcissism), it would be wrongheaded to hold him accountable for what he says. Trump would be more like an amoral natural disaster than like an evil genius.

Plus, Trump's obviously a bullshitter who's not remotely interested in telling the objective truth, so nothing he says should be taken at face value. He speaks only to sell, to con, and to aggrandize himself.