What typically happens is that people buy up these clothes in massive auction/lots, then just sell them on Amazon. As Amazon joins all listings together, 100 sellers of the same item all have the same reviews/etc.

So some slightly damaged shirt, or a shirt returned and such, ends up sold by these secondary sellers as new. This is part of why people destroy clothes upon return, so that secondary sellers can't buy their own returned product at $1, and sell it making more than the original seller would have.

Not to mention, all returns I've been noticing, resold from Amazon, are heavily treated now with some sort of spray. I can only presume bedbugs were getting returned with used clothing...