Clip 5 – 9 November 2018 - Law 14
Ross Moriarty of Wales breaks but Alex Dunbar (12) of Scotland tackles him from behind and brings him to ground.
It is a tackle.
Law 14.1: For a tackle to occur, the ball-carrier is held and brought to ground by one or more opponents.
Moriarty pushes the ball back to his side.
Law 14.7: Tackled players must immediately:
a. Make the ball available so that play can continue by releasing, passing or pushing the ball in any direction except forward. They may place the ball in any direction.
The ball is away from Moriarty when Jonny Gray falls on it.
Law 14.8: Other players must:
a. Remain on their feet when they play the ball.
'Other' players are those who are not the tackled player and not the tackler(s).
The referee was right to penalise Gray.