That Newsnight interview - if HH had spoken as a human being instead of as a lawyer, she could have dealt with the issue fairly effectively.
There is a context to PIE, I've spoke to some pesky rights-hoarding radical feminists who were around at that time, and who unreservedly condemned PIE, which surprisingly from today's perspective, was not universal.
There was a lot of “I may disapprove of what you say, but I will defend to the death your right to say it.” going on, libertarian mind-dances around the limits of human rights. And PIE was probably a handful of men with a typewriter, and NCCL wasn't a quango yet.
So HH could have said, yes it was a terrible mistake, NCCL got caught up in wishy-washy late hippy 60s libertarianism, we let anybody with a grievance and ten quid join, the awareness around sexual abuse of children was not as developed then as it later, quite rightly became, in retrospect it was wrong to take their ten quid and let them join, even though that did not technically 'affiliate' PIE and NCCL, and I was never actually 'involved' with PIE.
Yes I should have been more critical, I shouldn't have just followed the anything-goes libertarian mindset of NCCL at the time, it was wrong, I was wrong, I accept that and apologise, full stop.
I still think it would disqualify her from being head of EHRC but she could at least have redeemed herself a bit as a human being who got it seriously wrong in the 70s and now sees that sometimes what is not, or not yet, illegal can still be morally wrong.