The Ninth Circuit has held that the Board of Immigration Appeals (Board) may not apply the maxim "falsus in uno, falsus in omnibus" (false in one, false in all) to reject evidence submitted with a motion to reopen based on a previous adverse credible determination rendered by an Immigration Judge against the applicant. Because the Board has limited factfinding power (and a finding applying the falsus maxim requires factfinding), it must accept all evidence submitted with a motion to reopen as credible unless the evidence is inherently unbelievable.
The full text of Yang v. Lynch can be found here: http://cdn.ca9.uscourts.gov/datastore/opinions/2016/02/26/12-71773.pdf