I'll make my original point again. THIS YEAR the linesmen are being told not to put their flag up, until the player in an offside position TOUCHES the ball. So Benni wasn't flagged for the long ball through the middle. Nor was he offside when Roberts played it to him, because as Stuwilky says, you can't be offside when you are behind the ball.
I think the confusion about not being offside when the ball is passed backwards, is just an illustration because if it is passed backwards, the player must have been behind the ball. If you are behind the ball, you can't be offside.