Scam to Get Free Articles?

I sometimes troll Craigslist gigs to see what's out there (I know what some are already thinking -a scam on Craigslist -no!!) and found someone looking for articles. They were offering above average prices, at least for someone advertising publicly. So I wrote a sample article and then he wrote back to me saying it didn't pass Copyscape. I found this strange, since I wrote the article using no automated tools.

When you think about it, though, that could be an effective way to get a bunch of free articles -at least if you think like a low level scam artist. Advertise for articles, offer good pay, send each writer a different topic, then claim they didn't pass Copyscape.

This is why it can be risky to do any kind of freelance work without getting paid up front. Of course, it works the other way too -some "writers" will take your money and not do the work. While such things happen on forums like this, when you're dealing with Craigslist or other wide open platforms, the risk goes up substantially.

Is it even possible to write an original article and have it not pass Copyscape? I don't subscribe to the paid version, since I almost never buy content. I can see that no content can be 100% unique, but I'd think that something you write from scratch would have to be 90%+ or so.