All Crew Members wear Restraint Harnesses thus the Crew Member should not have been able to fall from the Aircraft.
The referenced article says the crew "has" restraint systems, not "wear" them. Huge differnce. You can not wear a restraint system like a gunners belt all the time, especially for a crew chief who must re-position often when checking on loads, acting as a spotter in the side door, moving up to talk to the pilots, operating a ramp, ramp gun, etc. They are not clipped in all the time. Rear ramp (upper and lower) and side door is often open. Also has a "hell hole"
Sad news.