Reading an older friend's report on hearing d'Amboise speak, another friend wrote her, livid. She was there at some events d'Amboise describes (a trip to Paris, I believe) and her recollection of it is completely different than his.
It sounds like d'Amboise may be like Arthur Mitchell - a great raconteur, but I'd double check everything.
This reminds me of a comment Federico Fellini is said to have made about the autobiographical elements in films like Amarcord. It went something like this: When it comes to memory, imagination and telling a good story are more important than accuracy. (Think Proust, rather than Pepys.)
For memoirs, however, or history ... I'm not so sure. Anyway, I'm still looking forward to spending some hours with d'Amboise, when the book arrives.