It looks (and sounds) to me like the first put-back (reverse lay-up attempt) was released before the shot clock buzzer and subsequently hit the back "flange/brace" of the basket. So no shot clock violation. Then the second put-back beat the game clock horn.....
Comment: seems that there should be two different sounds for a shot clock violation and the game clock expiration. I think the defensive team thought the game was over after the shot clock buzzer went off. They seemed to quit after the first put-back/buzzer....