engine run?
Ummm,
When I went to airplane mechanic school, engine runs were performed from the safe environs of the cockpit (unless, of course, the engine exploded, then, not so safe..).
I can only imagine a few scenarios where one would be aside the engine at power (with the cowling presumable open) to tweak something on the fuel control. Maybe. While the engine was running.
Certainly not on a hi-bypass fan. The JT8, maybe, but it's more run, shutdown, tweak and run again.
Maybe the guy was looking for a leak at power. Maybe it wasn't even an engineer, maybe a chock thrower got too close.
Somebody lost an arm, and that is way wrong. Shouldn't happen. Jets have been around way too long for these stupid accidents to continue. And yes, props have killed more ground/flight people than jets, on the ground.
PB