Hand on ground.

Jannie du Plessis of the Sharks is playing loosehead for his side at a scrum where Dewaldt Duvenhage of the Stormers is to put the ball in.

The referee goes through his CROUCH, TOUCH, PAUSE, ENGAGE.

On engage the two front rows come together and the props bind.

Law (c) Binding by loosehead props. A loosehead prop must bind on the opposing tighthead prop by placing the left arm inside the right arm of the tighthead and gripping the tighthead prop’s jersey on the back or side. The loosehead prop must not grip the chest, arm, sleeve or collar of the opposition tighthead prop. The loosehead prop must not exert any downward pressure.
Sanction: Penalty kick

Du Plessis does not bind on Brok Harris at all. He puts his hand on the ground and then curls in to collapse the scrum.

He certainly deserved to be penalised.