I tested this by choosing to search for something completely random that would return unusual results and give a decent indicator of whether or not DDG was just copy-pasting results, so to speak. I searched for "extent space taco secure", no quotations. Bing seems to have exploded when I searched for this. The results are completely nonsensical and seem to have nothing to do with what I searched for. The first two hits are to Google, the first about webhp (apparently some virus?) and the other to their chrome page. Other links include things like links to fidelity.com, americanexpress.com, and the huffington post front page.
DDG's results are [mostly] reasonable and populated mostly by things like some recent event where the head of NASA mentioned space security. Though it does have a link to the SF bay area craigslist alongside a couple of other really weird ones. In any case, you can see for yourself. Suffice to say they're definitely not just replicating results, at least not from Bing.