Holy Crap!

did it hang up or did it just pull him under? it looks like he initially got yanked in and under and is just stunned, and then he moves/adjusts and well, the rest...

i watched that initial sequence a few times, but didn't go full on zapruder on it.
It appears the lathe hung up for a few seconds. I didn't notice it turning when he became hung under it. But I'm like you, I didn't get the magnifying glass out. Either way, it's a real shame. Someone right there might have had enough time to stop it. He was still alive until it began spinning him. It was all over from the first revolution.