Speaking as a former EMT, I can tell you that I never unbuckled a seriously injured victim of a car accident. On the other hand, I cannot count the number of times that a seriously injured accident victim was removed (and often succumbed later to his/her injuries) who had NOT buckled up but suffered massive injuries from being unrestrained in a crash. Force equals mass times velocity. It's physics, the same physics that governs the motion of aircraft.
The Boeing engineer was correct. They normally don't leave final assembly at the factory in that coating, but are painted to customer requirements. Fuselages, however, are built in Wichita, Kansas, by Spirit AeroSystems and are transported, with the green coating, by rail to Boeing's Seattle-area facilities. You will find plenty of photos of these airplanes-on-flatcars on-line. There was a notorious rail accident in Montana or Idaho a few years back in which some of the railcars left the tracks, spilling green 737 fuselages into a river. The unfortunate airplanes were immediately christened "Salmon-thirty-salmons."
Spirit AeroSystems is what used to be Boeing's Wichita factory, but it was spun off some years ago.
Reform has been needed for a long time. Where the "designated representative" philosophy once worked, it no longer does, due to ever-growing shareholder pressure on aircraft manufacturers to increase profitability and business schools' emphasis on same.