Florida Man
Cartoon expert and crap superhero
Let's consider context to determine this.The fact that the conversation took place is the proof. It can also be logically inferred that both of them interpreted it differently, or that one of them is lying on national TV to avoid being embarrassed. Unlike RD’s claims, admitting the conversation taking place is ample evidence that it happened.
On one hand, you have Bernie who has spent literally decades championing women's rights, promoting their participation in politics, and even saying that women could become President on multiple occasions. Is there video proof of this? Yes. Is there written proof of this? Yes. Did Bernie encourage Warren to run for President in 2016? Yes. Is there proof of this? Yes.
On the other hand, you have Elizabeth Warren who has been a Republican her whole life until some years ago while championing her Native American heritage and even using it to get into law school. Is there proof of her heritage? No. Is there proof that her Native heritage is bullshit? Yes, because 1/1024 is 1/1024. She also accuses Bernie for saying a woman can't be President, not in late 2019 when the story came out, but arbitrarily from 2018. Is there proof of this? No.
So while I can't prove she was lying, the context here shows that it is far more likely she lied about it, and on national TV at that. And look what it did for her. Good job Warren.