Falsifiability is, unfortunatey, a bias against things that might exist in nature but that are not-consistent. If there were a quantum field lifeform, a ghost if you will, or even something more unusual like a hostile entity or a demon, that entity might get angry and shove somebdy down the stairs or scratch someone or attack somebody. The problem is that such an entity is not going to be as consistent as Maxwell's equations or gravity. Basically, such an entity might exist but would always be falsified by a standard physics test. What say you?