Mark

Standard practice for myself and most others....

Engine cleared. Cones or any ground items pulled safely away. 

Exhaust  area  cleared or blocked by vehicles.

Visual of both inlet and tail pipe.

MAN ON HEADSET AT NOSE GEAR IN CONTACT WITH MECHANIC PERFORMING RUN.

Beacon on.

Ground man verifies area cleared before start. I just read about accident.  It sounds like the mechanic walked into the inlet air path. This is where experience rules.  If you have a inexperienced mechanic..... EXPLAIN THE DANGER BEFOREHAND!

You have no second chance with your actions.