I assume that the victims were already outside the aircraft and were hit by flying debris?
Accurate details of what occurred seem to evade this tragedy. The only person who actually knows what happened is the driver who's testimony, we are being told, is unreliable.
If the Daily Mirror is to be believed the victims were "hacked to death by blades of helicopter" but, that's the Mirror.
There is a tendency in many of the northern territories - Alaska, Canada, Scandinavia - to request pax to crouch down next to the helicopter after disembarking and remain so until the heli leaves.
If they were not under the disk then I imagine they were fairly close to it and which seems a shame give the vast expanse available to them.