Listen to the referee.

Pierre Spies, the Bulls' No.8, picks up at the back of the scrum. He beats Tim Boys and then two Highlanders grab him -  Steven Setephano, and flyhalf  Mat Berquist. They bring Spies down. Setephano also goes to ground. We have a tackler and a tackled play in terms of the law. Berquist does not go to ground but he clings like a limpet to the ball and eventually the Highlanders get it out.

The referee penalises Berquist.

Right?

Yes.

The following is contained in a recent - earlier this month - ruling by the Designated Members of the International Rugby Board, the men tasked to get the laws straight.

Players who were attached to the player who is tackled and who remain on their feet must release the player and the ball (Law 15.6 (c)) and then may play the ball in accordance with Law 15.6 (b).

This refers to Berquist. He had to release Spies and the ball.

Law 15.6 OTHER PLAYERS
(c) Players in opposition to the ball carrier who remain on their feet who bring the ball carrier to ground so that the player is tackled must release the ball and the ball carrier. Those players may then play the ball providing they are on their feet and do so from behind the ball and from directly behind the tackled player or a tackler closest to those players’ goal line.
Sanction: Penalty kick