Designed experiments *attempt* to establish causation. They don't necessarily do so, as they can (and often do) establish instead a causal link via a secondary system.
In this case, for example, the actual research article states that the researchers believe the magnetic fields disrupt the ability for the subject to properly evaluate the intentions of the story protagonist, thus altering the outcome of their moral evaluation. This is different from fundamentally changing the subject's underlying moral framework.
Thus, the current study does show a causal link, but only between magnetism and perception, not a causal link between magnetism and morality.
By the current logic, if I throw a brick at your face and you stopped walking, I could then argue that bricks thrown at faces cause legs to cease functioning...
....prepares to be buried for daring to argue with the reductionists...