This is a great question. The answers I see are great suggestions. I little story. I have been using my aka since maybe 2003. First in chats, the forums, then publishing sites and more. That aka has become popular as others modify it as Tsmog, and TSmog and more. I do not have a registered trademark on it so fair game as they say. Yet tsmog holds true to any and all content that I publish. That aka is tracked miraculously with IP addresses and such too.
I wrote a poem I really, really would like to publish here at hubpages. However, I published it somewhere else and kinda' think it was a chat. Well, I get a duplicate warning when I try to publish here at hubpages and other self-publishing sites.
Consider the ethics and integrity, which hubpages seeks with their endeavor and more so the partnered relationship with Google. If Google flags it then Hubpages will flag it. The same goes if a hubber flags it, then hubpages will flag it. The same goes if a 'reader' foreign to hubpages flags it, then hubpages will flag it. Remember the process is canned or it is an automated system.
I suggest seeking out some Free duplicate search sites and run one or two of your hubs through them. If the results are positive, then document those results with a print screen and copy/paste method for future communications for a 'human' review. Help the person upline or pay it forward methodology comes into the process.
Bear in mind Hubpages, which is both a business venture and a community, is not the 'rule maker.' per se with the confines of Terms of Service with the larger picture. They are the rule enforcer, however they are only so many 'humans' shall we say. Yet, powerfully, they too are like your free legal aid or resource for assistance. Providing (for the sake of a term) evidentiary support offers a more powerful approach.
Oddly, sharing, most of my duplicate warnings are 'NOT' from me copying someone else. They are from me copying 'myself' in the past somewhere else on the internet. Remember, once published, authorship is claimed and does become a source. The wizardry of the internet is not refined to the point of that likely hood of knowing 'who' the author is, only there is an article or publication that is being duplicated.
In other words the article in publishing is considered the authority first. If you are quoting an article or source or resource, and it is not generic in content, then it is a duplicate. The property is the article or intellectual content.