If it’s a modern operation they’d be automatically and individually plucked out of the ingress path, or if it’s an older one they’d invalidate all the shoes in their bin at some earlier “bulk metal detection” step. And either way, those shoes would have to be disposed of in some other manner.

I get the “big company bad” crowd, but I mean.. what alternate option did Dow have in this case? (From the article Dow appears to be throwing contractors under the bus — plausibly, in my opinion, based upon the article. But let’s assume that the ‘malfeasance’ here was done directly by Dow — what’s the “right thing” they should have done when receiving donated intentionally-tampered-with shoes that would have damaged their machinery?)