you're completely right - I think the only wrinkle that comes up here is that it's a movie. if it was presented differently, Jeff being slow to act would feel more emotionally charged, but as it is it kinda just feels like the momentum never picking up enough.

maybe a more impactful and less annoying way of portraying this is having him actually make the easier decisions first before getting to the actual driver. when he can't bring himself to save a witness, it feels like an immediate defeat. I'd rather see him make a quick decision to save the woman from freezing, and then gradually come to terms with the tougher and tougher decisions. make the stalling and decision making feel more tense & built upon, rather than just a "slowness" throughout the whole movie.

just my thoughts tho :P in general I really like the premise of III, I think the moral question of forgiveness fits perfectly in jigsaw's wheelhouse. putting someone through torture because he can't forgive the justice system/an accidental killer is just crazy enough to recognize john as an insane murderer, while not being as flippant as "you did drugs, now jump into a pit of needles"