Is an expiatory offering (kaffarah) for breaking an oath obligatory upon one who swore to the veracity of a piece of news, believing it to be true, but then it became apparent to him that the news was false, knowing that he did not intentionally lie at the time of swearing?

If someone swears an oath believing something to be true, and it later turns out to be false, this is considered a "laghw" (unintended or vain) oath for which no expiation is required according to many scholars. This is based on the Almighty’s saying: "Allah will not impose blame upon you for what is unintentional in your oaths, but He will impose blame upon you for what your hearts have earned [through intention]" and His saying: "Allah will not impose blame upon you for what is unintentional in your oaths, but He will impose blame upon you for what you intended of oaths."