Not according to the investigator, who not only determined that there was no alcohol involved, Dunn was not responsible in any way, but that the late Mrs. Biden was. This story is tragic enough, garners plenty of sympathy for Biden -- for him to lie, embellish the tale is not only despicable, but dishonors his family, especially to do it for political gain, votes. It is wholly unnecessary.
All that I can say is that the story Biden tells is the one that was circulated among their friends at the time. I seem to remember some anger toward the fact that the truck driver was getting off without any punishment. No one blamed Neilia (I think that they called her, Neily) It could be exactly as is reported in this article, though. I just find it difficult to criticize Biden for repeating the story that was commonly circulated by their friends.