Durant in iso situation at the end of the game clock

Ibaka sets screen for Westbrook

Westbrook comes off the screen and continues to a set a ball screen

Durant comes off the screen attacking Westbrook's defender (X1) to try to freeze him and get Westbrook a shot
 

However, Westbrook's defender (X1) stays on Westbrook (i.e. good defense)

Therefore, Ibaka's defender (X4) has to help keep Durant out of the lane because X1 stuck with Westbrook

Durant kicks to Ibaka for corner 3pt shot

Cook spaces to the corner and Muhammed crashes the offensive glass