Yes, in the sense that if the witness gives evidence in court it is admissible and not hearsay, but if that person tells a third party and that third party repeats it, the third party's statement is hearsay.
If I persuaded him to post here, no one would believe it was him.
The book reference is good enough for me, I have no reason to believe that CAL would make up her sources and Bird is still alive to refute the claim. It would be a silly thing to do and it would ruin her reputation.
Thanks for clearing up the hearsay aspect, although I didn't introduce it and I don't believe it's even relevant to the original discussion but gringo seems to think we're in court.