Suppose Suzie in Alabama calls Bonnie in Arizona, and records the call without telling Bonnie. Alabama and Arizona are both one-party consent states, so this recording is legal.
Suppose that for some reason, this phone recording becomes a critical piece of evidence in a case that is being heard in California. California is a two-party consent state, so it would have been illegal to make the recording there. But since the recording wasn't made in California, would the California court allow it to be used?