If someone tells you that George Bush is not the 43rd president of the United States, they might be engaged in wishful thinking, or denial, but if they make that claim, it's either true or false! And you can assess that, regardless of whether there's an omniscient narrator, or an unreliable narrator, or it's shot in vérité, or it's manipulated, it's agitprop, whatever! It makes no difference! It's a style!