Not so much about the decision itself, but about the way in which the Law is worded.
On the weekend I was Ground Marshal for Subbies Div 4 finals. Sydney Irish v Redfield preliminary.
Irish take a goal line drop out quickly, and not all their players are behind the line (most are still retreating from the field of play).
Ball goes 5m, Irish player who kicked it regathers and play goes on.
Relevant Law is here:
https://www.world.rugby/the-game/laws/law/12 and states
19. The team-mates of the kicker must be behind the ball when it is kicked. Those who are in front of the ball when it is kicked may be sanctioned unless they retire and do not interfere with play until they are put onside by the actions of a team-mate. Sanction: Scrum.
This is interesting to me, because yet again it isn't really clear what the intent of the Law is:
The team-mates of the kicker must be behind the ball when it is kicked.
yet also and simultaneously:
Those who are in front of the ball when it is kicked may be sanctioned unless they retire and do not interfere with play until they are put onside by the actions of a team-mate.
The sanction is scrum, so how is a ref supposed to apply this? Could go either way in this instance.
In this case the basic application of "material effect" applied and I think was the right call at the time. However when the basic principles of offside are taken into account, you could easily take the path that Irish should have waited until everyone was onside.
The ref isn't wrong in either case, which means the Law, as it is written, is superfluous. "Punish them for (thing) unless (other thing that immediately and obviously contradictory)" is not a great way to run a ship...