I feel for you there LW, coming from a trade background myself. I've seen people wounded from the mistakes of others- including my own mistakes, and been wounded by theirs. Often born out of the mind-addling repetition of some particular job or project. Although there is never any intent, you carry that survivor guilt for the rest of your days.
It's made worse too when you see the shiny *****, suits and bean-counters reducing lunch breaks from an hour to 45 minutes, to 20, and then doing away with tea breaks etc. You need that time to restore your thought processes and reaction times, and bond with the people whose lives are in your hands and vice versa.
And speaking of fingers and work accidents, my late father had the end of his middle finger missing from when he was a mechanic in his 30's. He was working on a drum brake on a car when he asked the TA to raise the jack a notch, but the kid miss-understood and let it down. Quick job, no stands or even the removed wheel under the car for safety. My now-retired brother-inlaw's was his own doing though- apprentice Cabinet maker, pushing timber through the buzz saw- "Oh crap- that's my little finger sitting on the bench"......... Weird thing is, for many years he would get phantom pain or go to scratch the itch on the half that's missing.
I wasn't even allowed to touch the big angle grinder in the first couple of years of my apprenticeship, and now I cringe when I go into B's and see the equipment for sale and hire that any joe can walk in off the street and hire or buy.