Obviously I do not know the circumstances in this particular case, but I always remember the gist of what Bob Grimstead said many years ago about prop-swinging on you own. His wise words go something like:
1) Tie the stick back and apply handbrake if there is one.
2) Set and lock the throttle at the appropriate setting.
3) Chock the wheels.
4) Tie the tail to something solid with a method of releasing it when in the cockpit after start.
5) Switch the fuel OFF. (The engine will normally run more than long enough for you to get round and switch the fuel on again after a successful start. Try it. You will be surprised how long your engine will run particularly at low revs with the fuel switched off!)
Only then swing the prop using the other normal precautions. You cannot be too careful imho.
PS In single seaters like the Turbulent, D5, Colibri etc, stand behind the prop, in front of the wing with one hand on the switches or throttle.
PPS Obviously, point the plane away from other people, aircraft or solid obstructions!