The perimeter game is a staple of the Spurs' offense, but so is the low-post game with Duncan and the pick-and-roll with Tony Parker.
Duncan got his points against Gasol on the block, but Pau forced him into Antoine Walker-level shooting percentages in order to get them. And on the screen/roll, he moved quickly enough to hedge off Parker from turning the corner, giving his guard time to recover while not allowing the dump-in to Duncan. He played absolutely perfect screen/roll defense.
Duncan played equally good man defense in the post, but his inferior athletic ability (and Bryant's superior jumpshot relative to Parker's) caused him to be abused on the pick-and-roll with Kobe Bryant.
I'm a huge Tim Duncan fan, but he was outplayed as a defender in this series by Gasol.
But yes, you do have to credit Fisher, Farmar, Vujacic, Bryant, and Radmanovic for their quickness recovering to the Spurs' shooters.