Granted, given Joe's apparent lack of mental awareness, senility a good case could be made he's too far gone to know.
Other than joe was a well known plagiarist in law school, and a presidential race, suggesting he plays fast and loose with the truth already.
https://www.nytimes.com/1987/09/18/us/biden-admits-plagiarism-in-school-but-says-it-was-not-malevolent.html
https://www.snopes.com/fact-check/joe-biden-plagiarism/
Joe also lies about the death of his wife for votes, empathy from crowd.
https://www.washingtontimes.com/news/2019/oct/18/joe-bidens-false-claim-about-drunken-driver-draws-/
Joe hasn't earned the benefit of the doubt concerning his family's grifting.