I was playing quite happily and just went to glance at my game with the same player to see what colour I was. Wasn't sure how to open it but managed it. Go back a few seconds later and I've lost for "leaving the game"! This seems to be a new feature I wasn't expecting.
I've often left games in this way for short times. The opponent gets more time if my clock runs down and I may still be thinking about the move.
This is the game. Both players on 1.39 out of 2 minutes.