It's not really a bug. The auto-resign countdown kicks in when:
a) The opponent is not making their first move.
b) The opponent's network has disconnected.
If they correct the issue before the allotted time has lapsed, the timer stops and the game continues.
If the game is already underway, such as yours was, and the opponent has not made a move for a certain long period of time, it's possible they may be auto-resigned without the timer. It's unclear exactly what the site's protocols are on this matter - people are always complaining on the forums about unfair cutoffs. I've never had much of a problem with it.
it is a bug, right?
oh and just noticed when he had 0:10.5 sec it auto resigned