Hmm this is not rare. See the 4th move of white in this game also.
It seems it is just a display bug as players seemingly can't "hit" the blot and as one can see later in the game(6th move) when the white checker leaves that point the black checker is revealed again.
(peida) Kas Sul on sageli ajaületusi? Tasulised liikmed saavad "Automaatne vaheaeg" kaudu seada vaheajapäevi, kui muidu oleks ajaületus. (pauloaguia) (näita kõiki vihjeid)