A. Helicopter above the maximum 200 foot limit for helicopters in that space.
B. Absence of second controller that could focus on helicopters’ flight and correct, AT LEAST, the height to the proper 200 or below foot limit. If that happened even seeing the jet would not matter and the helicopter would pass undereath it, as designed and practiced in that airspace.
I may be jumping the gun here as there could be more significant facts to come out, but these two facts are central to the accident. And they are so interrelated. Hard to separate.
P.S. Did not see controller question height of helicopter in audio, maybe I am wrong but I did not see it.