I write a lot about oil and gas issues. I was in that business for 22 years. A lot of other people write about it on Hubpages and other sites. Some material is going to look similar because the issues are the same--just the opinions differ.
If a hub is suspected of being a duplicate, why not identify the other source so you can see what the moderator is talking about. It is a pretty one sided issue.
Finally, I thought it was all right to share hubs on other sites. I wrote a hub and I was requested by a site in the United Kingdom to run it, with no compensation, but they included a link back to HubPages.
Is passing along my own work to other sites duplicating materials. If I own the copyright, I do not see where HubPages should have a problem.