Much like compressive or tensile forces, responsibility is perfectly capable of fully inhabiting every step of a series.
So if you put a linear stack of styrofoam blocks (negligible weight but some structural strength) and then put a 10 lb weight on top, every block in the stack experiences 10 lbs of force.
In the same way, I think every person along such a chain of custody can each, independently, be held fully responsible for a fuckup that makes its way down that line.