If only for a split second you should be fine - Remember the spark you get when you first plug in a battery to an ESC - This is like a short as the Caps soak up the voltage very quickly.
I'd be suprised if you've puffed it - Check your voltage on all cells. Post up a picture...
But be careful! Not worth buring the house down...
Dupe post -
http://www.rc-monster.com/forum/showthread.php?t=14988