This helicopter was operating at very low level. We don't know whether the multicopter in question was being flown LoS or FPV - if it was indeed being flown LoS then the helicopter had started low-level flight without an adequate check that the area was clear of veessels, vehicles, structures or people. That's an PIC's obligation and serious offence in most jurisdictions.
There was no collision, so the erroneous* claim that a collision would automatically be the drone operators fault doesn't apply. The actual collision was with a tree which failed to "give way to any manned aircraft". Presumably you'd now expect the tree to have been arrested and placed in front of a grand jury?
The instructor was reportedly conducting low-level hover taxiing training. But he had chosen an area which, when he had needed to perform an evasive manoeuvre, put him in conflict with a tree. That suggests that either his choice of suitable training area was seriously flawed, or his situational awareness was lacking. After all, SC has many large native birds, and he could just as easily have needed to manoeuvre to avoid a bird as a multicopter.
So I wouldn't be as quick to apportion blame here...
* There would be a presumption, but there are plenty of circumstances in which blame for a collision would lie with the helicopter pilot