What do you call?

[archer]

Friday night I was working a game with a new official in our crew. He was our linesman. During the 3rd quarter the wide out leaves the huddle and goes out of bounds and stands beside his coach. After a few seconds he steps back in and stands behind the linesman who happens to be standing about 15 ft. in the field of play. I thought it looked like an act of deception because the defense never even noticed the player standing about a yard into the field of play. I killed it and went and reported it as an act of deception. Our referee said this was legal because he was within 15 yds of the huddle when the ready for play whistle was sounded. He waved my flag off and no harm was done. Could he have been flagged for going out of bounds on his own and returning to the field of play? Does this rule only apply to after the snap or can it be applied when offence is set?