So in the example given, they actually have to retire to 2m behind where the ball was kicked from ? (just checking)
And in a case of the ball merely scuffing off a boot and trickling forward 1m, they'd have to retire 9m behind where the ball was kicked?
didds
For me .. on this one I would use the 2017 law.
In general I think approach (3) Is the only sensible one , but in this case is seems so clearly a mistake I would have to use approach (4)