Hmmm, it seems Flordia is having it's fair share of "odd" accidents this week....
But, let's give the benefit of the doubt to the pilot. Perhaps he did land and shut down, but just forgot to turn off the mags. Then, as he "inspected" the tail rotor, he accidently "hand propped" it, and off it went on its own! It's unfortunately common in the fixed wing world...