You think 13.3 trumps 21.10....
but I don't -- the two Laws work beautifully together - you can score a try from TIG but only when you are on your feet
Consider a parallel example : what are the requirements for making a tackle ?
[LAWS]REQUIREMENTS FOR A TACKLE
14.1 For a tackle to occur, the ball-carrier is held and brought to ground by one or more opponents.
14.2 Being brought to ground means that the ball-carrier is lying, sitting or has at least one knee on the ground or on another player who is on the ground.
14.3 Being held means that a tackler must continue holding the ball-carrier until the ball-carrier is on the ground.[/LAWS]
Note it doesn't say anything about having to be on your feet. So can you make a tackle from the floor? Yes ?
No, because of 13.3
[LAWS]A player on the ground without the ball is out of the game and must:
Allow opponents who are not on the ground to play or gain possession of the ball.
Not play the ball.
Not tackle or attempt to tackle an opponent.[/LAWS]
It's the same thing
Players on their feet can play the ball and make tackles
Players off their feet can not play the ball and cannot make tackles