It was a few years ago, but it was one of those fascinating morning sessions at the National when a singer is interviewed (in an informal setting)about the influences on their singing. Except, as far as I can remember, Martin volunteered loads of stuff without having to be asked. I think the reference to Fanny Blair was part of a general topic of why he still sang songs he'd been singing for years and years, and dropped others. He just didn't feel comfortable singing Fanny Blair any more.
But the whole subject is much more delicately nuanced now than it would have been when the broadsides were published. Child abuse v false memory etc. Just think of all the current problems with allegations by schoolchildren against teachers.....