That's my guess. The heli pilots certainly would have heard a clunk or impact of some sort. Speculation as wellSomebody has jumper to A LOT of conclusions without any proof or facts.
A lot of questions for sure. Was she in a "restricted / NFZ" when she flew? Maybe, don't know. If she had checked to make sure she was clear to fly and got "zero" indications of manned aircraft flying in her area and at only 150 feet - then the chopper "may" have been flying too low.
We have power company chopper flying at treetop level here in the mountains "trimming" trees along power lines with hanging chainsaws. I have flown from my yard - which is in no "restricted / NFZ" when they were around. Barely hear the chopper, but can hear the saws when cutting. Since they were a good 100 yards away from my home - I popped up to treetop level and got some photo's / video's of them in action. When they started to move - I brought the drone down below treetop (about 75 ft) and stayed clear.
A bit different in a place like FL - where it's pretty flat, but does have 75+ ft pine / other trees.
Maybe they can provide the flight logs and someone can check them to "verify" the story and lack of real info. I'm inclined to think it got hit with prop wash and sent to the ground.
Until then - ALL SHEER SPECULATION!