Oddly enough, I've never worked for the EFDSS, so came into contact with the results of Peter Kennedy's work through my own fieldwork in Castleton, Derbyshire from 1965. Even at that time, he was already gaining a questionable reputation and later rumours swirled around the 'real' reason for his sudden departure from the EFDSS.
From the point of view of people in Castleton however, it was his apparent thoughtlessness that caused them real difficulty. He made a series of BBC radio programmes using his earlier recordings but never contacted any of the people whose contributions he used to let them know about the broadcasts. In consequence, some people missed their chance to hear themselves (quite a big deal then) and more seriously, one family suddenly heard the voice of their recently dead father coming out of the radio and - as you might imagine - were thoroughly shocked as a result. Yes, it was lack of consideration for contributors' feelings, rather than anything more blameworthy, but the human results for contributors in Castleton were significant all the same.
He could also demonstrate amazing cheek. Once contacting Radio 3 to claim he'd been "shocked to the core" that a series I'd written and presented for them had not consulted him about the use of "recordings of traditional folk musicians, especially as many of them were in fact my own recordings".
Subsequently, he wrote to Manchester University Press (the original publishers of my book, The Imagined Village) demanding to know why I hadn't "sought the co-operation of the one living authority who has the necessary experience and knowledge on the subject [of the Folk Revival]" before it was issued. Because the book contained references to his parents, Douglas and Helen Kennedy and aunt, Maud Karpeles, he claimed that "on moral grounds" he should have "received a copy for checking before publication" and "a small royalty on sales or an outright sum based on the number of words employed". The publishers did not agree to this.
He also recorded at least one programme I made for Radio 2 off air and put it up for sale in the Folktrax catalogue. Perhaps I should have claimed "a royalty" for this, but he didn't choose to contact me about it.
I met him a few times and (even after the publications of The Imagined Village) we had perfectly pleasant conversations, particularly about Maud Karpeles. But claiming "moral grounds" for his actions and asserting his ownership of recordings he'd made while working for the BBC or recorded off-air can't be justified.