http://www.youtube.com/watch?v=r_wdK6nTAVg
Check the 1:43 mark.
Nunes originally was marked by Abidal, but Abidal unfortunately fell asleep and stood there like a statue. Chryg also didnt look too awesome when he went up to head the ball away but missed it, b/c he could have still saved the ball if he kept his original position. Its by far the lesser mistake ofc, but when you leave your position and approach the ball, you better get it headed away. Puyol was just the poor dog left with 2 attackers in a bad situation where you always look unfortunate, but he couldnt do much here. Sticking to his man and the far post was imo actually the right thing in general, in order to clear deflections etc.