Brian, the foundation is not the "source of authority" on what did or
didn't happen years before they existed. The sources of authority
would be those people who were actually present and involved in the
situation.
I'm sure that the entire company wasn't solely Jimmy and Larry. There
are probably others who were employees or whatever who could also be
interviewed on the matter.
As well there are archives of what Jimmy and Larry did or didn't say,
and when and to whom. The foundation really is irrelevant in writing
the "History of Wikipedia: The First Two Years". They aren't even a
primary source.
Will Johnson