well, hang on -- up above everyone is telling me that the defending team is gaining sn advantage - sn unfair advantage indeed - by having no one in the tramlines. (although of course in reality they are not)one assumes its advantage played anyway.
The real question is at what juncture does that call get made i.e. "playing advantage - no tramline player" or similar.
Id suggest its once the ball has left the throwers hands as up until then in reality the lineout hasn't "started" [ cue 17 page discussion about when a lineout begins.,.. ]