Why Did Referee Courtney Kirkland Try to Block a Kris Humphries Free Throw? [Video]

During Wednesday night’s Nets-Raptors game, Kris Humphries went to the line for two free throws. After making his first, he is given the ball to shoot his second. That’s when referee Courtney Kirkland realized that Jose Calderon was waiting to check in. Instead of blowing his whistle and waving his arms, he ran at Humphries and attempted to block his free throw attempt. Why did Kirkland not just blow the whistle? Will we ever see anything like this again?