The referee was happy with the try-scoring part but referred the knock down to the TMO, asking whether it was a charge-down or a knock-on.

The TMO advised that it was a charge-down and not a knock-on, and so the try was awarded - seven more points to the Cheetahs who won the match 36-19 in Invercargill.

Law 12 DEFINITION - KNOCK-ON
A knock-on occurs when a player loses possession of the ball and it goes forward, or when a player hits the ball forward with the hand or arm, or when the ball hits the hand or arm and goes forward, and the ball touches the ground or another player before the original player can catch it.
‘Forward’ means towards the opposing team's dead-ball line.
EXCEPTION: Charge down. If a player charges down the ball as an opponent kicks it, or immediately after the kick, it is not a knock-down though the ball may travel forward.

Ebersohn did charge the ball down. Immediately after the kick? That, obviously, is left to the referee's discretion, in this case advised by the TMO.

Ebersohn is a metre or two in front of Sopoaga when Sopoaga kicks the ball. Ebersohn shoots his arms up wife, hands open flat and facing ahead. Neither arms not hands look to be trying to catch the ball but block it. The ball strikes Ebersohn's left forearm. It certainly looks as if he was not trying to catch the ball,

The law that decided that a charged-down kick was not a knock-on was introduced in 1950 at the proposal of the Irish RFU. Later there was a tag added - that the player was not attempting to catch the ball.