1) He had no angle. The player was side on to him. 2) Not close enough to play. He could easily have been closer. 3) Based on the way the AR's responded to every out I doubt his pre-game instructions were for them to "assist him" as per the usual method for LOTG.
He also missed another tackle that was a penalty on Labinot Haliti due to being 45metres away from it (jogging, not even trying to make an effort to get near the incident). He was very inconsistent in my opinion largely due to poor positioning.