"Three to go, One to say No!"
In the States, the FAA considers the Med Crew to be part of the aircraft crew.
Unfortunately, that allows repositioning legs to be conducted under less stringent guidelines, eg. Pt. 91 vs. Pt. 135.
Technically speaking, there are no prescribed en route Minimum Safe Altitudes (over an uninhabited area such as where this event took place) and without a regulatory "hard deck" the issue becomes one of a careless and reckless attitude.
Used to fly Medevac/ Search & Rescue and besides a risk matrix, we used that expression- "Three to go, One to say No!" to categorize overall aeronautical decision making.