just my opinion, but in watching video and recreations of flight paths, it seemed to me, the helicopter pilot was trying to get in the way of plane, since I don’t see how anyone could make so many “mistakes” in such a short time as happened, to bring the helicopter not only up but also drift more and more into the path of oncoming plane. the H pilot was almost constantly off their flight path for many minutes before the accident.
I also blame control tower for not clearly telling the helicopter to stop and hover, instead of just asking questions about altitude etc and letting them proceed when controller could see for many minutes it would be close before it even looked like a hit. Controller had ability they did not choose to use.
She wasn't listening to the IP who was 4 feet away, why listen to ATC when you are on a 'mission'.