How can World Rugby say the referee made an error when they wrote the law that says the ref is the sole judge?
Because that particular piece of law is clearly absurd.
To take it to the extreme to indicate the point.
Red 4 punches blue 4 in full view of our hypothetical (sole Judge of fact and law DURING the game [ Not during and not after!]) referee. Referee stated " Red 4 yo uhave clearly punched Blue 4. Scrum down Blue put in.
As the "sole judge of fact and law " is he correct? Clearly not. Why has advisors / assessors if the referee is always right?
The point of that bit of law surely is just saying that DURING the game the referee makes the call and the players must accept it an get on with it. After the game any error thart was made can be dealt with as a training and development issue.
So, yes WR can sat the referee made an error.