Her allegation never sounded like Biden.
It has all the hallmarks of a swiftboat attack. Undermine and neutralise a candidate's comparative strongpoint using a fake narrative.
Trouble is, we know the playbook. They used it on Kerry. So we expect it again. This won't be the only example.
Now we know this. The Bananarepublicans are trying to undermine the sense that Biden is trustworthy and compassionate. Because that is his strength and Trump's great weakness.
So look for that angle in every seemingly randomly-generated anti-Biden story. This is part of the Trump campaign. It's how they fight. Because they lose every other way.