I think they call that "eating their own"...I am surprise Warren would just opt to come out of the blue given her credibility issues and say something she can't back up.  Though I've heard she has upwards of four people whom she talked about the conversation with after it happened but only a couple wanting to get involved enough to say she did but no names have been put forth so far.  

I wonder if this was something contrived between her and CNN to cut into Bernies support among women as of the recent poll showing him pulling out in front of Biden whose obviously seen by them as the only one able to defeat Trump...but that kind of finagling didn't get them very far in the last presidential election but none the less they are so over the top to defeat Trump a tactic such as this wouldn't be surprising.  She could have just came out and said it and they seen it as a prime opportunity to drive their agenda toward a Biden nomination.  It's CNN so who really knows, it's this kind of disparagement that has lost them a huge chunk of their audience.