Okay, lessons of heavy machinery:

You'll fuck up. One day, somehow, your hand will get snagged because the silicone folds around one of your fingers or an arm or that dangling attachment at his waist will get pulled into the silicone and drawn through, and yes, you're right, the possibility is really unlikely of it all going wrong. That's why you can do it for days on end and it's totally fine, weeks, years.

Then Steve gets added to the silicone roll one day.

That's the thing about heavy machinery, odds are this is a really easy job that they're trained for... but the point is that when you work with heavy machinery you realize that training doesn't amount to shit when it comes to the comedy of errors that so LOVES to happen and in those instances you can't hit an emergency stop nearly as well as you'd think you can. Once you start getting dragged into a machine, it's goodbye higher thinking hello lizard brain panic. Sure, you MIGHT have the sense of mind to remember where that stop button is in time, but these are FAST rollers, and you have microseconds between 'oh fuck' and 'AHHHHHHGODMYARMHELPIAAAARGH!'

Accidents are inevitable. They're always trying to happen, and that's why we have safety measures, because with the best trained people and every safety lockout protocol in the world, some fucker STILL gets killed by these machine. It's a numbers game, and every machine is not so much 'if' it kills someone but, if it has a human operator around heavy machinery, 'when'. Maybe someone got high. Maybe a safety valve broke. Heavy machinery, when you work with it, is just a yawning deathtrap and this dude is tapdancing around the edge of the void.