The review concluded that Welby, as the leader of the Church, had not been sufficiently curious about the allegations when he was made aware of them in 2013, and that it was unlikely he had not known before then.
He has always denied being aware of Smyth's behaviour before that year.
Welby had previously resisted calls to step aside over his response to the case, and when the Makin Review was released in November he insisted he did not have to resign. But days later, he said in a statement that he "must take personal and institutional responsibility" for his response to the scandal.
He said at the time that he stepped down "in sorrow with all victims and survivors of abuse".
In his interview with the BBC, Welby expressed concern about the pressure on public figures, saying there can be a "rush to judgement".
"Having been the object of that question [over whether to resign], it's a very difficult one to answer because you think: am I letting people down? Is it the right thing to do? It's a complicated question.
"I think there is a rush to judgement, there is this immense - and this goes back half a century - immense distrust for institutions and there's a point where you need institutions to hold society together.
"There's an absence, I'm not talking about safeguarding here, there is an absence of forgiveness; we don't treat our leaders as human.
"We expect them to be perfect. If you want perfect leaders you won't have any leaders."
https://www.bbc.co.uk/news/articles/c89y9g83e92o
Well no, actually. If leadership is unaccountable it will continue to lie, to mislead, to divert, to cover up.
If the most competent people refuse to take leadership roles because we expect them to be perfect, and lesser candidates take on the job and always tell the truth without misleading or diverting or covering up, then the lesser candidates are a better choice for leader.
Being excellent at a job is a lesser consideration than being completely truthful at all times, definitively so in a priest. I don't care whether the Archbishop has backed himself into a corner over a reasonable definition of "know". When he absolutely did know he still didn't do what he ought to have done. He put the institution above those he should have protected, and twelve years on from there he's still refusing to acknowledge that this was wrong. It was not a difficult question at all at the time and it isn't now.