Who's lying? (III)

Peter Oborne hasn't given in, despite all the scepticism aimed at him. That said, I'm puzzled. Mr Oborne originally said:

I have talked to senior BBC executives, and they tell me they personally think it’s wrong to expose lies told by a British prime minister because it undermines trust in British politics. 

Today he's focusing on something he heard second hand ("on excellent authority") i.e. somewhat saying that Tony Hall had said something - which is rather less impressive:

Peter Oborne: Three days ago I called the BBC press Office. I told them I had been told on excellent authority that BBC Director General Tony Hall has recently said that in no circs would the BBC call Boris Johnson (or any PM) a liar. I asked for confirmation or denial or even contextthis remark. We agreed a 5pm deadline for an answer. None came, so I pressed the BBC press office a second time the following day. When I finally received a statement from the BBC press office it made no attempt to deal with my question re Tony Hall. So I rang up the press office a third time and was told that a non-answer the only answer I was going to get. So I am asking Tony Hall over Twitter to answer the question I repeatedly put to the BBC press office over the last few days and which it has failed to answer.

Oddly, Lord Hall hasn't replied yet.