I took the previously posted video from inside the landing helicopter, enhanced a small region of the frames using Davinci Resolve, and extracted 3 still images which I post here.
I think that it is clear that the second, Taking-off, helicopter can be seen in the video. However, the video quality is abysmal, and the Aussi News logo plastered all over it, makes it worse!
Additionally I suggest as follows:
1} The 2nd heli would be easily visible to unobstructed human eyeballs. The difficulties in seeing it are all due to the lousy video quality. Hence, the passengers spotted it without difficulty. (On the video there is also a barely-visible flickering of white blades, but this is not captured by the stills.)
2} However, it does appear that the 2nd heli is constantly behind the windscreen sidepost, from the POV of the Pilot. This is very unfortunate.
3} The 2nd heli appears to hardly move relative to the ground behind and below it, due to the closing speeds and directions of the 2 Helis. It moves slightly to the right, towards a building, as shown. This is also very unfortunate.
Just my 10 cents worth!
IB