Legal consensus is that Joe can be sued for defamation. Remember that the facts show that Joe like Bill Clinton made his remarks before he was President. Rittenhouse was, was made a “public figure” for the purposes of defamation law, and would have to show that any defendant acted with “actual malice” — that is, with reckless disregard for the truth. He could arguably do so for Biden’s false statement.
A tweet included footage of the white racists in Charlottesville. When the audio from Chris Wallace related to violence in Kenosha was played, the clip showed a picture of Kyle, 18, brandishing a semi-automatic rifle.