I think that he got the patent because his demonstration did, indeed, show that the car mounted magnets could be moved by the stator magnets in the tracks beneath it. However, because of the very powerful rare earth magnets he used, that car had to have a heavy weight resting on it to hold it down on the tracks. The demonstration was impressive, but it is easy to ignore the energy he had to put into the system in order to position the car on the tracks. Then when the car is released, it goes flying off the end of the tracks. It's really no different then just compressing a spring and then releasing it...energy out = energy in.The bottom line is, the patent was based on an appeals board who saw a plastic toy car propel itself across a series on magnets not unlike what today we call a smot.
In Johnson's patents, nowhere does it say that his devices are producing energy so he really does not claim OU/PM. That, most likely, is why the received the patents in the first place.
If magnetic forces are truly conservative, then building a rotary machine using Johnson's design should not be able to produce any motion whatsoever. I tend to think that if it was possible, then it would have been done by now...
ken