Advice please

dave adams

Keen but green
Blue eight makes a run and is stopped by gold eight but both players stay on their feet. He manages to turn , shielding the ball, but is temporarily isolated from his team mates. No maul has formed
Gold five runs around blue eight and attempts to rip away the ball, thereby obstructing blues arriving team mates from assisting. The ball is trapped until gold eight wrestles him to the ground.
My question is whether gold five is offside or not?
Can anyone point me towards the relevant law that deals with this situation?