Unless I'm mistaken, this looks more like an exchange than a winning move.
"Game Abandoned" bug report

Maybe you disconnected man. Try contacting staffs, submit a ticket they will for surely see this problem of yours.
Here's the link:
http://support.chess.com/index.php?_m=tickets&_a=submit
I hope it will help you, Cheers! and good luck.
How can I have lost by "game abandoned" when I made the last move?
http://www.chess.com/livechess/game.html?id=71850252
What I saw was the other player never responding to my move and his clock running out. I understand it can seem like that when he really made a move that didn't reach my computer, but clearly that didn't happen.
Also, it's a bit weird that this happened after I made a winning move.
Not something I lose sleep over, but the people running the site might want to look at this.