That argument may or may not be true and really begs the relevant question: Did they know about the potential for strongmagneticfields to move ferrous metal components within their locks?
Solar experts believe that the tachocline may be the source of powerful magneticfields that produce strong solar flares and solar winds, and create sunspots that mysteriously appear and disappear during an 11-year cycle.
Such sculpted magneticfields that make up the magnetic bottle are not particularly strong, so the trick was to make antihydrogen atoms that didn't have much energy - that is, they were slow-moving.
Since nerve cells use electrical signals, and magneticfields can induce and disrupt such signals, a strong, well-aimed magnetic stimulation can affect the brain's operation.