This article is about Mars. But in 2021, Nestle and Cargill were involved in a Supreme Court case, where it was decided that the Alien Torts act could not used to bring suit by plaintiff who allege they were child slaves, trafficked from Mali to the Ivory Coast, forced to work, beaten, threatened, and not paid. The legal argument was not "we don't have child slave labor in our supply chain, even in areas where we are…
Your comment unhelpfully frames the issue as a dichotomy between "100% ethical labor" and "everything else", where "everything else" could mean anywhere between 0.01% unethical labor to 100% unethical labor. As a chocolate maker that's inevitably going to have unethical labor in the supply chain, the best legal strategy is to head off all claims by establishing a precedent that you're not responsible, rather than trying to quash each individual accusation of unethical labor.