@flannan: If anything, it being a factory makes the idea more eyebrow-raising. What's the Japanese equivalent of OSHA...? XD
A handyman working in such places frequently would definitely be at least aware of safety stuff even if they routinely and unprofessionally ignored it; conversely if this wasn't his usual sort of gig, that
also doesn't speak kindly of the choices made leading to the situation.
To be clear, my premise isn't that the situation is unrealistic; my premise is that for this to be the nature of the accident, someone (the protagonist or the person who hired him) would have to be grossly negligent.