PMD - Post Mint Damage.. not an error That did not occur at the Mint. Someone very creative with lots of time on their hands. How they did it.. Machine shop tooled.
Half of a Magician's coin? Crude machining https://www.cointalk.com/threads/help-opening-a-magicians-trick-coin.277507/#post-2399581
Oh yes he is joking.. And the only reason we joke like that is because this is what happens on Ebay all the time.. Someone finds a damaged coin and they call it a rare error. Sad thing is that newbies fall for it and spend tons of money on worthless junk!