http://www.thedailybeast.com/articles/2013/01/30/savaging-primitives-why-jared-diamond-s-the-world-until-yesterday-is-completely-wrong.html
I thought Corry's article was well written. I haven't read Diamond's supposed "rebuttle" but his quote from the Guardian article isn't very inspiring :
However, Diamond says Survival's condemnation of his book is driven by something other than facts. He argues its protectiveness toward tribal societies has led it to deny practices including warfare, infanticide, widow-strangling and abandoning the elderly. "Well-meaning defenders of traditional peoples, including apparently Corry, feel it necessary to deny the existence of those practices," he said. "That's a very bad idea – 'extremely dangerous', to use Corry's words where they really belong.
"Mistreatment of tribal peoples should be condemned not because you claim that they are peaceful when they really are not. It should instead be condemned on moral grounds: the mistreatment of any people is wrong."
I didn't see Corry denying any violence among tribal people, simply pointing out that Diamond's twisting of statistics to support his generalized conclusions is bogus. Makes you wonder whether Diamond even read the article.