I've never seen a case like this where it gets approved so i assumed it was outright forbidden.
I have. Its rare, but it happens; theres a repeated discussion just like this, the picture is approved/deleted, people eventually forget and the loop starts all over again.
That was silly of the uploader, why wouldn't s/he just create a sock puppet account with another name and upload it using that? It's easily done. Or have it someone else upload it. Damn, how silly of him/her.
Exactly. Like I said: Uploading own art is frowned upon, off course. The image per se looks absolutely fine, though. And because this flag reason doesn't mention quality issues, I think it's just again a hardline flag.
I think the quality is fine enough to be passed. If this is getting rejected because of self-uploading, then I believe the rule should be changed to just "prohibited" not "may be disputable".