I thought the plane and copter were flying under VFR rules and were too low to be tracked by FAA radar. That being said, the lack of attention by the controller during that time could have caused problems for other planes taking off or landing at Teterboro.
I’m not condoning in any way the lack of attention by the controller...BUT...If in fact the aircraft was flying to low to be tracked by radar and flight rules were VFR, how could the controller have known there was any danger?