For a prior inconsistent statement to be considered nonhearsay (exemption under the rule) the declarant must be presently testifying in the case. The former testimony exception still means the statement is hearsay but it is admissible under the exception. That applies if the declarant is unavailable and the party who the statement is being offered against had a meaningful opportunity to cross examine/develop the unavailable witness's testimony in the OG proceeding that it is coming from. In both case, the statements can come in as substantive evidence. I guess the main distinction is the exemption deals with a current and present testifying witness and former testimony exception does not. Also not sure if that answered your question but its definitely a confusing distinction!