Alternate angle shows that, after the buzzer sounded, Devin Booker walked over to the Clippers bench to taunt/gloat. The shove by Cousins followed shortly after:

Steph Curry hits a buzzer beater from half court to end the third quarter

Chris Paul dunks the ball and the Clippers bench goes crazy

Aaron Gordon shakes Ulis and dunks between Booker and Chriss!