The GMG on this situation is a Catch 22. Follow this:
Red throw-in, catch, bind and keeping the ball in the hands of the catcher (front player) they advance.
Blue, to avoid forming a maul and a PK for "leaving the lineout", step aside to leave a hole.
As Red advance Blue attempts to tackle the ball carrier. To do so they must leave the lineout!
This is the most idiotic, convoluted, unrealistic directive I have ever seen. And that's putting a positive spin on it!
Is this taken from the USA GMGs?
If so, who was the genius that added,
To do so they must leave the lineout!???
That differs to all of the reproductions (By Unions in Aus, NZ, and England) of the original memo that I have been able to find which all read;
"The attacking team would need to keep the ball with the front player if they were to drive down-field (therefore play on, general play - defenders could either engage to form a maul, or tackle the ball carrier.)"
There is no mention of the defending team having to leave the line out in order to attempt to tackle the ball carrier (the front man) in this situation.
If the attacking team decide to keep the ball with the front man (i.e. the jumper) and drive (waltz, stroll, meander, whatever) downfield, as soon as they have moved past the line-of-touch, the line out is over and we are in general play.
"...... if they were to drive down-field (therefore play on, general play........"
It is going to be difficult for the defending players to tackle the front man. Even if the attempted tackler manages to get a good hit on the ball carrier and is actually starting to bring him to ground, the ball carrier has team mates presumably bound to him and therefore can easily hand the ball to a team mate on the way down.
In the previous thread on this topic, the video of Ireland's #7 attempting to tackle the England ball carrier demonstrates how difficult making such a tackle will be.
If the attacking team move the ball to a player at the back of the group/"maul thingy", the line out is also over and once again we have general play. In this situation the ref calls "Use it". If they comply with the ref's call, it is play on. If they do not comply with the "use it" call the referee orders a scrum with the defenders to throw the ball in.
There is only one scenario that WR (IRB when the original memo was released) has not considered or given guidance on. I'm still waiting for someone on here to bring that one up. I'll leave it to the group to see if anyone can describe this scenario. Tick, tick, tick........