Einsteins theory often predate quantum mechanics and thusly quantum mechanics will cause "discrepancies" with standard Einsteinion physics. And thus very small amounts of matter and/or energy may react in very odd ways, see Schrodinger's cat. Also in the most extreme situations of quantum mechanics cause and effect are not clear and it can appear that cause fallows effect.
First, we have a living cat and place it in a thick lead box. At this stage, there is no question that the cat is alive. We then throw in a vial of cyanide and seal the box. We do not know if the cat is alive or if it has broken the cyanide capsule and died. Since we do not know, the cat is both dead and alive, according to quantum law, in a superposition of states. It is only when we break open the box and learn the condition of the cat that the superposition is lost, and the cat becomes one or the other (dead or alive).
We know that superposition actually occurs at the subatomic level, because there are observable effects of interference, in which a single particle is demonstrated to be in multiple locations simultaneously. What that fact implies about the nature of reality on the observable level (cats, for example, as opposed to electrons) is one of the stickiest areas of quantum physics. Schrodinger himself said, later in life, that he wished he had never met that cat.