At this point, a6 just makes the N go to d4, kicking again the BQ. A fool's play, but it is difficult for both sides to find the right path. White's defensive strategy has succeeded, and e4 is still to come - and possible. I suspect white is just playing around this (as he seems to indicate in his comment!)

30 seconds - far too much time ... for a GM who's a rook ahead.

Bad luck. Until the miscalculation the game was fairly even.

It's interesting to know that white had only 5 seconds, so if you could just hold mate off (maybe g6 instead of Rxa3) by just a little, just a couple of seconds, you could have won. This was a very interesting and educational game!

Eh my pride got crushed by the mishap but I was just holding on to see how long I'd last. It's amazing the vision a GM has over the board, even in blitz.