Here is the defense as far as I am concerned.
1. Ford claims that in addition to the Kavanaugh event, she has a genetic predisposition to PTSD and anxiety. Her own testimony.
2. There is a body of science that shows people with a genetic predisposition toward PTSD are more likely to produce false memories. Here is just one example, but there are many others:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5665161/To quote from the research:
"Our review suggests that individuals with PTSD, a history of trauma, or depression are at risk for producing false memories...."
Given that there is zero corroborating evidence, it is entirely likely that Dr. Ford is experiencing a false memory based on some event that happened to her in her teenage years. This is a more plausible explanation than the one that says Ford is telling the truth while four other witnesses are lying.