The shoulder portions of the five point harnesses on the 767 are the inertia type - so depending on the 'rate' it's quite feasible for a pilot to 'pitch' forward into the controls. Besides, he didn't need to suddenly 'pitch' forward - slumping forward would be sufficient and is unlikely to be fast enough to trigger the inertia reels.
Airbubba - I don't know if it was basic or an option - but as I recall the 767s I did flight tests on over the last 15 years all had electric seat adjusts - and most were new build freighters.