The law states, in relation, to what happened in today’s New Zealand v South Africa game

6.A.6 REFEREE CONSULTING WITH OTHERS

(a) The referee may consult with assistant referees in regard to matters relating to their duties, the Law relating to foul play or timekeeping and may request assistance related to other aspects of the referee’s duties including the adjudication of offside.

(b) A match organiser may appoint an official who uses technological devices. If the referee is unsure when making a decision in in-goal involving a try being scored or a touch down, that official may be consulted.

The official may be consulted if the referee is unsure when making a decision in in-goal with regard to the scoring of a try or a touch down when foul play in in-goal may have been involved.

The official may be consulted in relation to the success or otherwise of kicks at goal.

The official may be consulted if the referee or assistant referees are unsure if a player was or was not in touch when attempting to ground the ball to score a try.

The official may be consulted if the referee or assistant referees are unsure when making a decision relating to touch-in-goal and the ball being made dead if a score may have occurred.