Is it legal for a team to score a try from a line-out quick thrown-in after
- the same ball went into touch,
- the referee has blown for the lineout,
- the linejudge has his flag up and his arm out, and
- the defending team is still on their way to the line-out?
In this situation, the attacking team has an advantage as they outnumber the opposing team considerably, similar to when there are more players on one side of a formed line-out.
In my opinion, the referee should ensure that the line-out be formed properly as it already has been called. Furthermore, I believe a penalty kick should be awarded to the other team. This is due to the team taking the throw in being off-side as it cannot be judged a straight throw in.