The reason why I don't think it's a set up is he gave the pusher a pretty solid shot to the back, between the shoulder blades. That had to hurt. I'm thinking the pusher may have tried to mount that wall and jump on his own because he was afraid he was about to have the **** beat out of him.
The kid he pushed could have easily gone head first into the opposite wall, too, and had a serious spinal injury. Pretty stupid game to play if it was staged.