If there are 25 faceoffs in a game, you see that play 24 times. I can honestly say that I've never seen a trip called on it before. To be fair, I have seen interference called about 1 every 1,000,000 times but never @ 3-3 with 3 minutes left in a playoff game.
What is the league's motive in half of the things that come out of the league's office(or Werger's mouth)? A large majority of the decisions in this league are not in the best interest of essentially anyone, be it the players or the fans.