The Guardian did not issue a correction about Hersh's words. There was nothing to correct about them: the quote from Hersh is accurate. The Guardian issued a footnote/amendment (in their words), and here it is from the Guardian that you're referring to, as context:
> This article was amended on 1 October 2013. The original text stated that Hersh sold a story about the My Lai massacre to the New York Times for $5,000 when in fact it was the Times of London. Hersh has pointed out that he was in no way suggesting that Osama bin Laden was not killed in Pakistan, as reported, upon the president's authority: he was saying that it was in the aftermath that the lying began. Finally, the interview took place in the month of July, 2013.
Note that from this footnote that Seymour Hersh does not admit that he misspoke. He claims that he never suggested that Osama bin Laden was not killed. This is plainly a straight lie, given his claim that the White House's statement did not contain one word that was true.
If he wants to state that he misspoke in this interview: fine, then he should do it. But to state that he didn't make this claim is itself misinformation.
Edit: You're accusing me of bad faith. Can you please explain how my argument is deceptive or a lie? If anything, Seymour Hersh has acted in bad faith in this ordeal, lying about his own statements. And people should be suspect of him for that.