I doubt that he made anything up. Why would he if he's sitting there on that couch and carefully making contemporaneous notes. He could have stayed home and made things up. People may have told him things that were embellishments, but he's just reporting what they said. If he actually recorded it, say with a pen recorder, all the better, I assume he's quite used to people telling him things and then denying it later.
It's not really his job to discover if everything they said is true. Just like reporters tell us what Sarah Huckabee Sanders said and don't even try to verify any of it.
