You probably accidentally hit flip board. x on the keyboard does the same thing.
Hilarious bot glitch

Nope. Did not. It seems to happen if I use the button that randomly determines which side I play. If I choose to play white or black it does not happen.
I'm posting here because I can never seem to find the link to the beta forums.
I just played an entire game as the snowman.
Despite white being at the bottom of the board, I was in control of the black pieces.

Very interesting bug!