Original sentence: Keaggy has long insisted that such stories are completely unfounded and there is been no tangible evidence to confirm the accounts: "it was impossible that Jimi Hendrix could ever have heard me...[he] would never have said anything about a guy who, at the time, was only nineteen years old
Edited sentence: Keaggy has long insisted that such stories are completely unfounded, noting that "it was impossible that Jimi Hendrix could ever have heard me...[he] would never have said anything about a guy who, at the time, was only nineteen years old