Isn't the whole ISO business and industry standard practices put in place to prevent that and protect everyone: workers from getting injured on the job, bosses from having to pay enormous amount of money as compensation (the insurance will kick in if the company got his ISO and stuff right) and the insurance raking in money for forcing the workplace to be safer ? (I know reality isn't that rosy but that's the objective, right ?)

>that is morally as reprehensible as if that person held the knife. I think it should be treated as an assault.

Are you guilty for buying a cheaper produce when child labor was used to produce it? Does your knowledge of the abuse going into making it cheaper matter?

You are knowingly and directly allowing a child slave driver to profit from your purchase.

Where exactly do you absolve yourself of guilt in that transaction?

Absolutely.