I don't think they did. I searched for Tank Man, and the first result is the wikipedia article, followed by nothing but articles about him and the Tiananmen Square Massacre. The images section seems to be the only one that's acting weird, because if I search for "Tank Man China" it shows a bunch of pictures of him.
Doesn't DDG mostly rely on Bing for its results? So a result that's suspiciously missing from Bing would be likely to also be missing from DDG, unless their indexing and crawling is more comprehensive than I thought.
Three, arguably—Yandex still exists and is generally pretty decent in addition to being the best at dealing with Russian morphology (although relying on it after Segalovich’s death seems foolish).