Halachah does recognize that there are individuals who are so precise, both in perception as well as in their conveying of facts, that hearing their account is tantamount to witnessing the act in person. One would be permitted to believe even rechilus told by such individuals, but could not share the information with others.
As stated in the laws of loshon hora, the Chofetz Chaim contends that no one today can claim to posses this degree of integrity; therefore, one should not rely on this halachah in practice.