During an interview with Christine – 24:04-24:38:
https://www.youtube.com/watch?v=TL3pNADcsbQ
“There’s always been a kind of a loose sense of co-writership that has existed with the two of us. As someone who was producing those Fleetwood Mac albums, sometimes it’s a fine line between taking a strong hand in production and co-writing. And it may be the politics that dictate how you–you know–attribute credit for something like that. And that probably applied to Stevie as well.”