If its been posted in that section would the PPC treat it as a fanfic?

As a Lewis/Space Trilogy fan, it's doubly irritating. Livejournal, Fictionpress, DeviantArt, or any number of the support networks/communities out there. Egads, it's not that hard!

I'm pretty sure it's called FANfiction.net for a reason. I don't think it's confusion, either, all the other stuff on their profile is actual fanfiction. (Well, fanfic for Twilight, which reads like a badly written fanfiction itself, but that's not really the point.)
...I don't know, really. Probably laziness to check the rules properly, like you said.

I'd like to say things like this are caused by honest confusion, though that is a sign of being too lazy to read the content guidelines.
Mind you, we know that many writers on there don't read them, if only because the content guidelines also instruct writers to spellcheck and proofread their work, use proper formatting and respect their reviewers.