Unique Duplicate Content Issue

I have a site (2 years old) with very popular unique niche content.

A fellow SEO (3rd party) is working with my company to deliver traffic to my main site from his sites (flat fee, no PPC or PPA.) 3 months ago, he built a site that was completely duplicate content of my site. All of the links are going to my main site. I then asked to have it taken down, or rewritten in their own words. (surprisingly enough, this guy is good at building and maintaining rank. Strange that he'd do this)

He redid the site, but only barely rewrote the content, in that, they rewrote each sentence on every page a little differently from the original (as though they were in a rush to turn in a report in 7th grade History class.)

Is this going to be seen as duplicate content? I would tell him to scrap it all and do it from scratch, but he's gaining rank, building quality backlinks, and delivering traffic to me. He also has a couple links to my other sites that he didn't think about taking off.

Is it worth shutting off the link juice from these links as well as the traffic he's built just for the sake of a possible duplicate issue??

Thanks.

Here's the skinny... it may or may not get taken out... if it doesn't all the power to you...

If it doesn't however, there is no hope of recovery without a absolutely clean site and near 0% duplication. Best bet if it loses in Google to remove all linkage for 4 months, make clean... and in four months try again.

IMHO it's better to rewrite than redo completely but here's the rub... the guy has already been paid the maximum and each time he does something else he decreases his profitability... thus from a commerical vantagepoint - not profitable to lift another finger... unless their is more money on the table.

Thanks Fathom.

I'll probably just leave it then. My other concern, since my own site is only 2 yrs old, that Google may possibly see my site as the duplicate. I realize that domain age plays a role, as well as link age, but if their site becomes stronger than mine in the future, could it flip-flop making my site look like the dup?

Thanks again.

The site that links to the other will always be the culprit... it's only a toss up if they both link to each other.