Someone I used to know always grew Amnesia Haze, and I remember he took 8 amnesia seeds, and 1 blueberry for fun instead of all amnesia. And the blueberry turned out like yours. Maybe it's a 1 in a 100.000 chance you can get that? I have no idea.. Some genetic problem? Have seen it once before, was a few years ago, and don't have contact with the guy anymore, otherwise I would ask him if he knew.